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Mil-Std-882E Safety Analysis

System Hazard Analysis

In this 45-minute session, The Safety Artisan looks at System Hazard Analysis, or SHA, which is Task 205 in Mil-Std-882E. We explore Task 205’s aim, description, scope, and contracting requirements. We also provide value-adding commentary, which explains SHA – how to use it to complement Sub-System Hazard Analysis (SSHA, Task 204) in order to get the maximum benefits for your System Safety Program.

This is the seven-minute-long demo. The full video is 47 minutes long.

System Hazard Analysis: Topics

  • Task 205 Purpose [differences vs. 204];
    • Verify subsystem compliance;
    • ID hazards (subsystem interfaces and faults);
    • ID hazards (integrated system design); and
    • Recommend necessary actions.
  • Task Description (five slides);
  • Reporting;
  • Contracting; and
  • Commentary.
Transcript: System Hazard Analysis

Introduction

Hello, everyone, and welcome to the Safety Artisan, where you will find professional, pragmatic, and impartial safety training resources and videos. I’m Simon, your host, and I’m recording this on the 13th of April 2020. And given the circumstances when I record this, I hope this finds you all well.

System Hazard Analysis Task 205

Let’s get on to our topic for today, which is System Hazard Analysis. Now, system hazard analysis is, as you may know, is Task 205 in the Mil. Standard 882E system safety standard.

Topics for this Session

What we’re going to cover in this session is purpose, task description, reporting, contracting and some commentary – although I’ll be making commentary all the way through. Going to the back to the top, the yellow highlighting with this and with task 204, I’m using the yellow highlighting to indicate differences between 205 and 204 because they are superficially quite similar. And then I’m using underlining to emphasize those things that I want to really bring to your attention and emphasize. Within task 205, purpose. We’ve got four purposes for this one. Verify subsistent compliance and recommend necessary actions – fourth one there. And then in the middle of the sandwich, we’ve got identification of hazards, both between the subsystem interfaces and faults from the subsystem propagating upwards to the overall system and identifying hazards in the integrated system design. So, quite different emphasis to 204 which was really thinking about subsystems in isolation. We’ve got five slides of task description, a couple on reporting, one on contracting – nothing new there – and several commentaries.

System Requirements Hazard Analysis (T205)

Let’s get straight on with it. The purpose, as we’ve already said, there is a three-fold purpose here; Verify system compliance, hazard identification and recommended actions, and then, as we can see in the yellow, the identifying previously unidentified hazards is split into two. Looking at subsystem interfaces and faults and the integration of the overall system design. And you can see the yellow bit, that’s different from 204 where we are taking this much higher-level view, taking an inter subsystem view and then an integrated view.

Task Description (T205) #1

On to the task description. The contract has got to do it and documented, as usual, looking at hazards and mitigations, or controls, in the integrated system design, including software and human interface. It’s very important that we’ll come onto that later. All the usual stuff about we’ve got to include COTS, GOTS, GFE and NDI. So, even if stuff is not being developed, if we’re putting together a jigsaw system from existing pieces, we’ve still got to look at the overall thing. And as with 204, we go down to the underlined text at the bottom of the slide, areas to consider. Think about performance, and degradation of performance, functional failures, timing and design errors, defects, inadvertent functioning – that classic functional failure analysis that we’ve seen before. And again, while conducting this analysis, we’ve got to include human beings as an integral component of the system, receiving inputs, and initiating outputs.  Human factors were included in this standard from long ago.

Task Description (T205) #2

Slide two. We’ve got to include a review of subsystem interrelationships. The assumption is that we’ve previously done task 204 down at a low level and now we’re building up to task 205. Again, verification of system compliance with requirements (A.), identification of new hazards and emergent hazards, recommendations for actions (B.), but Part C is really the new bit. We are looking at possible independent, dependent, and simultaneous events (C.) including system failures, failures of safety devices, common cause failures, and system interactions that could create a hazard or increase risk. And this is really the new stuff in 205 and we are going to emphasize in the commentary, you’re going to look very carefully at those underlying things because they are key to understanding task 205.

Task Description (T205) #3

Moving on to Slide 3, all new stuff, all in yellow. Degradation of the system or the total system (D.), design changes that affect subsystems (E.). Now, I’ve underlined this because what’s the constant in projects? It’s change. You start off thinking you’re going to do something and maybe the concept changes subtly or not so subtly during the project. Maybe your assumptions change the schedule changes, the resources available change. You thought you were going to get access to something, but it turns out that you’re not. So, all these things can change and cause problems, quite frankly, as I am sure we know. So, we need to deal with not just the program as we started out, but the program as it turns out to be – as it’s actually implemented. And that’s something I’ve seen often go awry because people hold on to what they started out with, partly because they’re frightened of change and also because of the work of really taking note changes. And it takes a really disciplined program or project manager to push back on random change and to control it well, and then think through the implications. So, that’s where strength of leadership comes in, but it is difficult to do.

Moving on now. It says effects of human errors (F.) in the blue, I’ve changed that. Human error implies that the human is at fault, that the human made a mistake. But very often, we design suboptimal systems and we just expect the human operator to cope. Whether it’s fair or unfair or unreasonable, it results in accidents. So, what we need to think about more generally is erroneous human action. So, something has gone wrong but it’s not necessarily the humans’ fault. Maybe the system has induced the human to make an error. We need to think very carefully about.

Moving on, determination (G.), potential contribution of all those components in G. 1. As we said before, all the non-developmental stuff. G.2, have design requirements in the specifications being satisfied? This standard emphasizes specifications and meeting requirements, we’ve discussed that in other lessons. G.3 and whether methods of system implementation have introduced any new hazards. Because of course, in the attempted to control hazards, we may introduce technology or plant or substances that themselves can create problems. So, we need to be wary of that.

Task Description (T205) #4

Moving on to slide four. Now, in 205.2.2, the assumption here is that the PM has specified methods to be used by the contractor. That’s not necessarily true, the PM may not be an expert in this stuff. While they may for contractual or whatever reasons have decided we want the contractor to decide what techniques to use. But the assumption here is that the PM has control and if the contractor decides they want to do something different they’ve got to get the PM’s authority to do that. This is assuming, of course, that the this has been specified in the contract.

And 205.2.3, whichever contractor is performing the system hazard analysis, the SHA, they are expected to have oversight of software development that’s going to be part of their system. And again, that doesn’t happen unless it’s contracted. So, if you don’t ask for it, you’re not going to get it because it costs money. So, if the ultimate client doesn’t insist on this in the contract and police it to be fair because it’s all very well asking for stuff. If you never check what you’re getting or what’s going on, you can’t be sure that it’s really happening. As an American Admiral Rickover once said, “You get the safety you inspect”. So, if you don’t inspect it, don’t expect to get anything in particular, or it’s an unknown. And again, if anything requires mitigation, the expectation in the standard is that it will be reported to the PM, the client PM this is and that they will have authority. This is an assumption in the way that the standard works. If you’re not going to run your project like that, then you need to think through the implications of using this standard and manage accordingly.

Task Description (T205) #5

And the final slide on task description. We’ve got another reminder that the contractor performing the SHA shall evaluate design changes. Again, if the client doesn’t contract for this it won’t necessarily happen. Or indeed, if the client doesn’t communicate that things have changed to the contractor or the subcontractors don’t communicate with the prime contractor then this won’t happen. So, we need to put in place communication channels and insist that these things happen. Configuration control, and so forth, is a good tool for making sure that this happens.

Reporting (T205) #1

So, if we move on to reporting, we’ve got two slides on this. No surprises, the contractor shall prepare a report that contains the results from the analysis as described. First, part A, we’ve got to have a system description. Including the physical and functional characteristics and subsystem interfaces. Again, always important, if we don’t have that system description, we don’t have the context to understand the hazard analysis that had been done or not being done for whatever reason. And the expectation is that there will be reference to more detailed information as and when it becomes available. So maybe detailed design stuff isn’t going to emerge until later, but it has to be included. Again, this has got to be required.

Reporting (T205) #2

Moving onto parts B and C. Part B as before we need to provide a description of each analysis method used, the assumptions made, and the data used in that analysis. Again, if you don’t do this, if you don’t include this description, it’s very hard for anybody to independently verify that what has been done is correct, complete, and consistent. And without that assurance, then that’s going to undermine the whole purpose of doing the analysis in the first place.

And then part C, we’ve got to provide the analysis results and at the bottom of this subparagraph is the assumption. The analysis results could be captured in the hazard tracking system, say the hazard log, but I would only expect the sort of leading to be captured in that hazard log. And the detail is going to be in the task 205 hazard analysis report, or whatever you’re calling it. We’ve talked about that before, so I’m not going to get into that here.

Contracting

And then the final bit of quotation from the standard is the contracting. And again, all the same things that you’ve seen before. We need to require the task to be completed. It’s no good just saying apply Mil. Standard 882E because the contractor, if they understand 882E, they will tailor it to suit selves, not the client. Or if they don’t understand 882E they may not do it at all, or just do it badly. Or indeed they may just produce a bunch of reports that have got all the right headings in as the data item description, which is usually supplied in the contract, but there may be no useful data under those headings. So, if you haven’t made it clear to the contractor, they need to conduct this analysis and then report on the results – I know it sounds obvious. I know this sounds silly having to say this, but I’ve seen it happen. You’ve got a contractor that does not understand what system safety is.

(Mind you, why have you contracted them in the first place to do this? You should know that you should have done your research, found out.)

But if it’s new to them, you’re going to have to explain it to them in words of one syllable or get somebody else to do it for them. And in my day job, this is very often what consultancies get called in to do. You’ve got a contractor who maybe is expert building tanks, or planes, or ships, or chemical plants, or whatever it might be, but they’re not expert in doing this kind of stuff. So, you bring in a specialist. And that’s part of my day job.

So, getting back to the subject. Yes, we’ve got to specify this stuff. We’ve got to specify it early, which implies that the client has done quite a lot of work to work this all out. And again, the client may above the line, as we say, say engage a consultant or whoever to help them with this, a specialist. We’ve got to include all of the details that are necessary. And of course, how do you know what’s necessary, unless you’ve worked it out. And you’ve got to supply the contractor, it says concept of operations, but really supplying the contractor with as much relevant data and information as you can, without bogging them down. But that context is important to getting good results and getting a successful program.

Illustration

I’ve got a little illustration here. The supposition in the standard in Task 205 is we’ve got a number of subsystems and there may be some other building blocks in there as well. And some infrastructure we’ve going to have probably some users, we’re going to have an operating environment, and maybe some external systems that our system, or the system of interest, interfaces with or interacts with in some way. And that interaction might be deliberate, or it might be just in the same operating environment at night. And they will interact intentionally or otherwise.

Commentary – Go Early

With that picture in mind, let’s think about some important points. And the first one is to get 205, get some 205-work done early. Now, the implication in the standard by the numbering and when you read the text is that subsystem hazard analysis comes first. You do those hexagonal building blocks first and then you build it up and task 205 comes after the subsystem hazard analysis. You thought, “Well, you’ve already got the SHHAs for each subsystem and then you build the SHA on top”. However, if you don’t do 205 early, you’re going to lose an opportunity to influence the design and to improve your system requirements. So, it’s worth doing an initial pass of 205 first, top-down, before you do the 204 hexagons and then come back up and redo 205. So, the first pass is done early to gain insight, to influence the design, and to improve your requirements, and to improve, let’s say, the prime contractor’s appreciation and reporting of what they are doing. And that’s really, dare I say, a quick and dirty stab at 205 could be quite cheap and will probably the payback/the return on investment should be large if you do it early enough. And of course, act on the results.

And then the second part is more about verifying compliance, verifying those as required interfaces, and looking at emergent stuff, stuff that’s emerged – the devil’s in the detail as the saying goes. We can look at the emerging stuff that’s coming out of that detail and then pull all that together and tidy up it up and look for emergent behaviour.

Commentary – Tools & Techniques

Looking at tools and techniques, most safety analysis techniques that we use look at single events or single failures only in isolation. And usually, we expect those events and failures to be independent. So, there’re lots of analyses out there. Basic fault tree analysis, event tree analysis. Well, event tree is slightly different in that we can think about subsequent failures, but there’re lots of basic techniques out there that will really only deal with a single failure at a time. However, 205.2.1C requires us to go further. We’ve got to think about dependent simultaneous events and common cause failures. And for a large and complex system, each of those can be a significant undertaking. So, if we’re doing task 205 well, we are going to push into these areas and not simply do a copy of task 204, but at a higher level. We’re now really talking about the second pass of 205. The previous, quick and dirty, 205 is done. The task 204 on the subsystems is done. Now we’re pulling it all together.

Dependent & Simultaneous Events

Let’s think about independent simultaneous events. First, dependent failures. Can an initial failure propagate? For example, a fire could lead to an explosion or an explosion could lead to a fire. That’s a classic combination. If something breaks or wears could be as simple as components wearing and then we get debris in the lubrication system. Could that – could the debris from component wear clog up the lubrication system and cause it to fail and then cause a more serious seizure of the overall system? Stuff like that. Or there may be more subtle functional effects. For example, electric effects, if we get a failure in an electrical system or even non-failure events that happen together. Could we get what’s called a sneak circuit? Could we get a reverse flow of current that we’re not expecting? And could that cause unexpected effects? There’s a special technique we’re looking at called sneak circuits analysis. That’s sneak, SNEAK, go look it up if you’re interested. Or could there be multiple effects from one failure? Now, I’ve already mentioned fire. It’s worth repeating again. Fire is the absolute classic. First, the effects of fire. You’ve got the fire triangle. So, to get fire, we need an inflammable substance, we need an ignition source, and we need heat. And without all three, we don’t get a fire. But once we do get a fire, all bets are off, and we can get multiple effects. So, we recall, you might remember from being tortured doing thermodynamics in class, you might remember the old equation that P1V1T1 equals P2V2T2. (And I’ve put R2 that for some reason, so sorry about that.)

What that’s saying is, your initial pressure, volume and temperature multiplied together, P1V1T1, is going to be the same as your subsequent pressure, volume and temperature multiply together, P2V2T2. So, what that means is if you dramatically increase the temperature say, because that’s what a fire does, then your volume and your pressure are going to change. So, in an enclosed space we get a great big increase in pressure, or if we’re in an unenclosed space, we’re going to get an increase in volume in a [gas or] fluid. So, if we start to heat the [gas or] fluid, it’s probably going to expand. And then that could cause a spill and further knock-on effects. And fire, as well as effect making pressure and volume changes to the fluids, it can weaken structures, it makes smoke, and produces toxic gases. So, it can produce all kinds of secondary hazardous effects that are dangerous in themselves and can mess up your carefully orchestrated engineering and procedural controls. So, for example, if you’ve got a fire that causes a pressure burst, you can destroy structures and your fire containment can fail. You can’t send necessarily people in to fix the problem because the area is now full of smoke and toxic gas. So, fire is a great example of this kind of thing where you think, “Well, if this happens, then this really messes up a lot of controls and causes a lot of secondary effects”. So, there’s a good example, but not the only one.

And then simultaneous events, a hugely different issue. What we’re talking about here is we have got undetected, or latent, failures. Something has failed, but it’s not apparent that it’s failed, we’re not aware, and that could be for all sorts of reasons. It could be a fatigue failure. We’ve got something that’s cracked, or it could be thermal fatigue. So, lots of things that can degrade physical systems, make them brittle. For example, an odd one, radiation causes most metals to expand and neutron bombardment makes them brittle. So, it can weaken things, structure and so forth. Or we might have a safety system that has failed, but because we’ve not called upon it in anger, we don’t notice. And then we have a failure, maybe the primary system fails. We expect the secondary system to kick in, but it doesn’t because there’s been some problem, or some knock-on effect has prevented the secondary system from kicking in. And I suspect we’ve all seen that happen.

My own experience of that was on a site I was working on. We had a big electricity failure, a contractor had sawed through the mains electricity cable or dug through it. And then, for some unknown reason, the emergency generators failed to kick in. So, that meant that a major site where thousands of people worked had to be evacuated because there was no electricity to run the computers. Even the old analogue phones failed after a while. Today, those phones would be digital, probably voice over IP, and without electricity, they’d fail instantly. And eventually, without power for the plumbing, the toilets back up. So, you’re going to end up having to evacuate the entire site because it’s unhygienic. So, some effects can be very widespread. Just because you had a late failure, and your backup system didn’t kick in when you expected it to.

So how can we look at that? Well, this is classic reliability modelling territory. We can look at meantime between failures, MTBF, and meantime to repair (MTTR) and therefore we could work out what the exposure time might be. We can work out, “What’s the likelihood of a latent failure occurring?” If we’ve got an interval, presumably we’ve going to test the system periodically. We’ve got to do a proof test. How often do we have to do the proof test to get a certain level of reliability or availability when we need the system to work? And we can look at synchronous and asynchronous events. And to do that, we can use several techniques. The classic ones, reliability, lock diagrams and fault tree analysis. Or if we’ve got repairable systems, we can use Markov chain modelling, which is very powerful. So, we can bring in time-dependent effects of systems failing at certain times and then being required, or systems failing and being repaired, and look at overall availability so that we can get an estimate of how often the overall system will be available. If we look at potential failures in all the redundant constituent parts. Lots of techniques there for doing that, some of them quite advanced. And again, very often this is what safety consultants, this is what we find ourselves doing so.

Common Cause Failures

Common cause failure, this is another classic. We might think about something very obvious and physical, maybe we get debris, maybe we’ve got three sets of input channels guarded by filters to stop debris getting into the system, but what if debris blocks all the filters so we get no flow? So, obvious – I say obvious – often missed sources of sometimes quite major accidents. Or let’s say something more subtle, we’ve got three redundant channels, or a number of redundant channels, in an electronic system and we need two out of three to work, or whatever it might be. But we’ve got the same software working each channel. So, if the software fails systematically, as it does, then potentially all three channels will just fail at the same time.

So, there’s a good example of non-independent failures taking down a system that on paper has a very high reliability but actually doesn’t. Once you start considering common cause failure or common mode analysis. So, really what we would like is we would like all redundancy to be diverse if possible. So, for example, if we wanted to know how much fuel we had left in the aeroplane, which is quite important if you want the engines to keep working, then we can employ diverse methods. We can use sensors to measure how much fuel is in the tanks directly and then we can cross-check that against a calculated figure where we’ve entered, let’s say, how much fuel was in the tanks to start with. And then we’ve been measuring the flow of fuel throughout the flight. So, we can calculate or estimate the amount of fuel and then cross-check that against the actual measurements in the tanks. So, there’s a good diverse method. Now, it’s not always possible to engineer a diverse method, particularly in complex systems. Sometimes there’s only really one way of doing something. So, diversity kind of goes out of the window in such an engineered system.

But maybe we can bring a human in.

So, another classic in the air world, we give pilots instruments in order to tell them what’s going on with the aeroplane, but we also suggest that they look out the window to look at reality and cross-check. Which is great if you’re not flying a cloud or in darkness and there are maybe visual references so you can’t necessarily cross-check. But even things like system failures, can the pilot look out the window and see which propeller has stopped turning? Or which engine the smoke and flames coming out of? And that might sound basic and silly, but there have been lots of very major accidents where that hasn’t been done and the pilots have shut down the wrong engine or they’ve managed the wrong emergency. And not just pilots, but operators of nuclear power plants and all kinds of things. So, visual inspection, going and looking at stuff if you have time, or take some diverse way of checking what’s going on, can be very helpful if you’re getting confusing results from instrument readings or sensor readings.

And those are examples of the terrific power of human diversity. Humans are good at taking different sensory inputs and fusing them together and forming a picture. Now, most of the time they fuse the data well and they get the correct picture, but sometimes they get confused by a system or they get contradictory inputs and they get the wrong mental model of what’s going on and then you can have a really bad accident. So, thinking about how we alert humans, how we use alarms to get humans attention, and how we employ human factors to make sure that we give the humans the right input, the right mental picture, mental model, is very important. So, back to human factors again, especially important, at this level for task 205.

And of course, there are many specialist common cause failure analysis techniques so we can use fault trees. Normally in a fault tree when you’ve got an and gate, we assume that those two sub-events are independent, but we can use ‘beta factors’ (they’re called) to say, “Let’s say event a and event b are not independent, but we think that 50 percent or 10 percent of the time they will happen at the same time”. So, you can put that beta factor in to change the calculation. So, fault trees can cope with non-independent fate is providing you program the logic correctly. You understand what’s going on. And maybe if there’s uncertainty on the beta factors, you must do some sensitivity modelling on the tree with different beta factors. Or you run multiple models of the tree, but again, we’re now talking quantitative techniques with the fault tree, maybe, or semi-quantitative. We’re talking quite advanced techniques, where you would need a specialist who knows what they do in this area to come up with realistic results, that sensitivity analysis. The other thing you need to do is if the sensitivity analysis gives you an answer that you don’t want, you need to do something about that and not just file away the analysis report in a cupboard and pretend it never happened. (Not that that’s ever happened in real life, boys and girls, never, ever, ever. You see my nose getting longer? Sorry, let’s move on before I get sued.)

So other classic techniques. Zonal hazard analysis, it looks at lots of different components in a compartment. If component A blows up, does it take out everything else in that compartment? Or if the compartment floods, what functionality do we lose in there? And particularly good for things like ships and planes, but also buildings with complex machinery. Big plant where you’ve got different stuff in different locations. There’re also things called particular risk analysis where you think of, and these tend to be very unusual things where you think about what a fan blade breaks in a jet engine. Can the jet engine contain the fan blade failure? And if not, where you’ve got very high energy piece of metal flying off somewhere – where does that go? Does that embed itself in the fuselage of the aeroplane? Does it puncture the pressure hull of the aeroplane? Or, as has sadly happened occasionally, does it penetrate and injure passengers? So, things like that, usually quite unusual things that are all very domain or industry specific. And then there are common mode analysis techniques and a good example of a standard that incorporates those things is ARP 4761. This is a civil aircraft standard which looks at those things quite well, for example, there are many others.

Summary

In summary, I’ve emphasized the differences between Task 205 and 204. So, we might do a first pass 205 and 204 where we’re essentially doing the same thing just at different levels of granularity. So, we might do the whole system initially 205, one big hexagon, and then we might break down the jigsaw and do some 204 at a more detailed level. But where 205 is really going to score is in the differences between 204. So instead of just repeating, it’s valuable to repeat that analysis at a higher-level, but really if we go to diversify if we want success. So, we need to think about the different purpose and timing of these analyses. We need to think about what we’re going to get out of going top-down versus bottom-up, different sides of the ‘V’ model let’s say.

We need to think about the differences of looking at internals versus external interfaces and interactions, and we need to think of appropriate techniques and tools for all those things – and, of course, whether we need to do that at all! We will have an idea about whether we need to do that from all the previous analysis. So, if we’ve done our PHI or PHA, we’ve looked at the history and some simple functional techniques, and we’ve involved end-users and we’ve learnt from experience. If we’ve done our early tasks, we’re going to get lots of clues about how much risk is present, both in terms of the magnitude of the risk and the complexity of the things that we’re dealing with. So, clearly, we’ve got a very complex thing with lots of risks where we could kill lots of people, we’re going to do a whole lot more analysis than for a simple low-risk system. And we’re going to be guided by the complexity and risks and the hot spots where they are and go “Clearly, I’ve got a particular interface or particular subsystem, which is a hotspot for risk. We’re going to concentrate our effort there”. If you haven’t done the early analysis, you don’t get those clues. So, you do the homework early, which is quite cheap and that helps you. Direct effort, the best return on investment.

The Second major bullet point, which I talk about this again and again. That the client and end-user and/or the prime contractor need to do analysis early in order to get the benefits and to help them set requirements for lower down the hierarchy and pass relevant information to the sub-contractors. Because the sub-contractors, if you leave them in isolation, they’ll do a hazard analysis in isolation, which is usually not as helpful as it could be. You get more out of it if you give them more context. So really, the ultimate client, end-user, and probably the prime as well, both need to do this task, even if they’re subcontracting it to somebody else. Whereas, maybe the sub-system hazard analysis 204 could be delegated just down to the sub-system contractors and suppliers. If they know what they’re doing and they’ve got the data to do it, of course. And if they haven’t, there’s somebody further up the food chain on the supply chain may have to do that.

And lastly, 204 and 205 are complimentary, but not the same. If you understand that and exploit those similarities and differences, you will get a much more powerful overall result. You’ll get synergy. You’ll get a win-win situation where the two different analyses complement, reinforce each other. And you’re going to get a lot more success probably for not much more money and effort time. If you’ve done that thinking exercise and really sought to exploit the two together, then you’re going to get a greater holistic result.

Copyright

So, that’s the end of our session for today. Just a reminder that I’ve quoted from the Mil. Standard 882, which is copyright free, but the contents of this presentation are copyright Safety Artisan, 2020.

For More …

And for more lessons and more resources, please do visit www.safetyartisan.com and you can see the videos at www.patreon.com/safetyartisan.

End

That’s the end of the lesson on system hazard analysis task 205. And it just reminds me to say thanks very much for watching and look out for the next in the series of Mil. Standard 882 tasks. We will be moving on to Task 206, which is Operating and Support Hazard Analysis (OSHA), a quite different analysis to what we’ve just been talking. Well, thanks very much for watching and it’s goodbye from me.

The End

You can find a free pdf of the System Safety Engineering Standard, Mil-Std-882E, here.

Categories
Safe Design

Safe Design (Full)

Want some good guidance on Safe Design? In this 52-minute video from the Safety Artisan, you will find it. We take the official guidance from Safe Work Australia and provide a value-added commentary on it. The guidance integrates seamlessly with Australian law and regulations, but it is genuinely useful in any jurisdiction.

A free video on ‘Good Work Designis available here.

This is the three-minute demo of the full, 52-minute-long video.

Topics: Safe Design

  • A safe design approach;
  • Five principles of safe design;
  • Ergonomics and good work design;
  • Responsibility for safe design;
  • Product lifecycle;
  • Benefits of safe design;
  • Legal obligations; and
  • Our national approach.

Transcript: Safe Design

Click Here to Reveal the Transcript

Hello, everyone, and welcome to the Safety Artisan, where you will receive safety training via instructional videos on system safety, software safety and design safety. Today I’m talking about design safety. I’m Simon and I’m recording this on the 12th of January 2020, so our first recording of the new decade and let’s hope that we can give you some 20/20 vision. What we’re going to be talking about is safe design, and this safe design guidance comes from Safe Work Australia. I’m showing you some text taken from the website and adding my own commentary and experience.

Topics

The topics that we’re going to cover today are: a safe design approach, five principles of safe design, ergonomics (more broadly, its human factors), who has responsibility, doing safe design through the product lifecycle, the benefits of it, our legal obligations in Australia (but this is good advice wherever you are) and the Australian approach to improving safe design in order to reduce casualties in the workplace.

Introduction

The idea of safe design is it’s about integrating safety management, asset identification and risk assessment early in the design process to eliminate or reduce risks throughout the life of a product,  whatever the product is, it might be a building, a structure, equipment, a vehicle or infrastructure. This is important because in Australia, in a five-year period, we suffered almost 640 work-related fatalities, of which almost 190 were caused by unsafe design or design related factors contributed to that fatality., there’s an important reason to do this stuff, it’s not an academic exercise, we’re doing it for real reasons. And we’ll come back to the reason why we’re doing it at the end of the presentation.

A Safe Design Approach #1

First, we need to begin safe design right at the start of the lifecycle (we will see more of that later) because it’s at the beginning of the lifecycle where you’re making your bad decisions about requirements. What do you want this system to do? How do we design it to do that? What materials and components and subsystems are we going to make or buy in order to put this thing together, whatever it is? And thinking about how we are going to construct it, maintain it, operate it and then get rid of it at the end of life., there are lots of big decisions being made early in the life cycle. And sometimes these decisions are made accidentally because we don’t consciously think about what we’re doing. We just do stuff and then we realise afterwards that we’ve made a decision with sometimes quite serious implications. And, a big part of my day job as a consultant is trying to help people think about those issues and make good decisions early on when it’s still cheap, quick and easy to do. Because, of course, the more you’ve invested into a project, the more difficult it is to make changes both from a financial point of view and if people have invested their time, sweat and tears into a project, they get very attached to it and they don’t want to change it. there’s an emotional investment made in the project. the earlier you get in, at the feasibility stage let’s say, and think about all of this stuff the easier it is to do it. A big part of that is where is this kit going to end up? What legislation codes of practice and standards do we need to consider and comply with? So that’s the approach.

A Safe Design Approach #2

So, designers need to consider how safety can be achieved through the lifecycle. For example, can we design a machine with protective guarding so that the operator doesn’t get hurt using it, but also so the machine can be installed and maintained? That’s an important point as often to get at stuff we must take it apart and maybe we must remove some of those safety features. How do we then protect and maintain when the machine is maybe opened up, and the workings are things that you can get caught in or electrocuted by. And how do we get rid of it? Maybe we’ve used some funky chemicals that are quite difficult to get rid of. And Australia, I suspect like many other places, we’ve got a mountain of old buildings that are full of asbestos, which is costing a gigantic sum of money to get rid of safely. we need to design a building which is fit for occupancy. Maybe we need to think about occupants that are not able bodied or they’re moving stuff around in the building they don’t want to and need a trolley to carry stuff around. we need access, we need sufficient space to do whatever it is we need to do.

This all sounds simple, obvious, doesn’t it? So, let’s look at these five principles. First of all, a lot of this you’re going to recognise from the legal stuff, because the principles of safe design are very much tied in and integrated with the Australian legal approach, WHS, which is all good, all consistent and all fits together.

Five Principles of Safe Design

Principle 1: Persons with control. If you’re making a decision that affects design and products, facilities or processes, it is your responsibility to think about safety, it’s part of your due diligence (If you recall that phrase and that session).

Principle 2: We need to apply safe design at every stage in the lifecycle, from the very beginning right through to the end. That means thinking about risks and eliminating or managing them as early as we can but thinking forward to the whole lifecycle; sounds easy, but it’s often done very badly.

Principle 3: Systematic risk management. We need to apply these things that we know about and listen to other broadcasts from The Safety Artisan. We go on and on and on about this because this is our bread and butter as safety engineers, as safety professionals – identify hazards, assess the risk and think about how we will control the risks in order to achieve a safe design.

Principal 4: Safe design, knowledge and capability. If you’re controlling the design, if you’re doing technical work or you’re managing it and making decisions, you must know enough about safe design and have the capability to put these principles into practice to the extent that you need to discharge your duties. When I’m thinking of duties, I’m especially thinking of the health and safety duties of officers, managers and people who make decisions. You need to exercise due diligence (see the Work Health and Safety lessons for more about due diligence).

Principle 5: Information transfer. Part of our duties is not just to do stuff well, but to pass on the information that the users, maintainers, disposers, etc will need in order to make effective use of the design safely. That is through all the lifecycle phases of the product.

So those are the five principles of safe design, and I think they’re all obvious really, aren’t they? So, let’s move on.

A Model for Safe Design

As the saying goes, is a picture is worth a thousand words. Here is the overview of the Safe Design Model, as they call it. We’ve got activities in a sequence running from top to bottom down the centre. Then on the left we’ve got monitor and review, that is somebody in a management, controlling function keeping an eye on things. On the right-hand side, we need to communicate and document what we’re doing. And of course, it’s not just documentation for documentation sake, we need to do this in order to fulfil our obligations to provide all the necessary information to users, etc. that’s the basic layout.

If we zoom in on the early stage, Pre-Design, we need to think about what problem are we trying to solve? What are we trying to do? What is the context for our enterprise? And that might be easy if you’re dealing with a physical thing. If you build a car, you make cars to be driven on the road. there’ll be a driver and maybe passengers in the car, there’ll be other road users around you, pedestrians, etc. with the physical system, it’s relatively easy with a bit of imagination and a bit of effort to think about who’s involved. But of course, not just use, but maintenance as well. Maybe it’s got to go into a garage for a service etc, how do we make things accessible for maintainers?

And then we move on to Concept Development. We might need to do some research, gather some information, think about previous systems or related systems and learn from them. We might have to consult with some people who are going to be affected, some stakeholders, who are going to be affected by this enterprise. We put all of that together and use it to help us identify hazards. Again, if we’re talking about a physical system, say if you make a new model of car, it’s probably not that different from the previous model of a car that you designed. But of course, every so often you do encounter something that is novel, that hasn’t been done before, or maybe you’re designing something that is virtual like software and software is intangible and with intangible things it’s harder to do this. It requires a bit more effort and more imagination. It can be done, don’t be frightened of it but it does require a bit more forethought and a bit more effort and imagination than is perhaps the case with something simple and familiar like a car.

Moving on in the life cycle we have Design Options. We might think about several different solutions. We might generate some solutions; we might analyse and evaluate the risks of those options before selecting which option we’re going to go with. This doesn’t happen in reality very often, because often we’re designing something that’s familiar or people go, well actually I’m buying a bunch of kit off the shelf, (i.e. a bunch of components) and I’m just putting them together, there is no optioneering to do. That’s actually incorrect, because very often people do optioneering by default, in that they buy the component that is cheap and readily available, but they don’t necessarily say, is the supplier going to provide the safety data that I need that goes along with this component? And maybe the more reputable supplier that does do that is going to charge you more. you need to think about where are you going to end up with all of this and evaluate your options accordingly. And of course, if you are making a system that is purely made from off-the-shelf components, there’s not a lot of design to do, there is just integration.

Well that pushes all your design decisions and all your options much earlier on in the lifecycle, much higher up on the diagram as we see here. we are still making design options and design decisions, but maybe it’s just not as obvious. I’ve seen a lot of projects come unstuck because they just bought something that they like the look of, it appealed to the operators (If you live in an operator driven organisation, you’ll know what I mean).me people buy stuff, because they are magpies and it looks shiny, fun and funky. Then they buy it and people like me come along and start asking awkward questions about how are you going to demonstrate that this thing is safe to use and that you can put it in service? And then, of course, it doesn’t always end well if you don’t think about these things up front.

So, moving on to Design Synthesis. We’ll select a solution, put stuff together, work on controlling the risks in the system that we are building. I know it says eliminating and control risks, if you can eliminate risks that’s great, very often though you can’t. we have to deal with the risks that we cannot get rid of and there are usually some risks in whatever you’re dealing with.

Then we get to Design Completion, where we implement the design, where we put it together and see if it does come together in the real world as we envisaged it. That doesn’t always happen. Then we have got to test it and see whether it does what it’s supposed to do. We’re normally pretty good at testing it for that, because if you set out requirements for what it’s supposed to do, then you’ve got something to test against. And of course, if you’re trying to sell a product or service or you’re trying to get regulators or customers to buy into this thing, it’s got to do what you said it’s going to do. there’s a big incentive to test the thing to make sure it does what it should do. We’re not always so good at testing it to make sure that it doesn’t do what it shouldn’t do. That can be a bigger problem space depending on what you’re doing. And that is often the trick and that’s where safety get involved. The Requirements Engineers, Systems Engineers are great at saying, yeah, here’s the requirements test against the requirements. And then it’s the safety people that come along and say, oh, by the way, you need to make sure that it doesn’t blow up, catch fire, get so hot that you can burn people. You need to eliminate the sharp edges. You need to make sure that people don’t get electrocuted when operating or maintaining this thing or disposing of it. You must make sure they don’t get poisoned by any chemicals that have been built into the thing. Even thinking about if I had an accident in the vehicle, or whatever it is that has been damaged or destroyed, and I’ve now got a debris spread across the place, how do we clear that up? For some systems that can be a very challenging problem.

Ergonomics & Work Design

So, we’re going to move on now to a different subject, and a very important subject in safe design. I think this is one of the great things about safe design and good work design in Australia – that it incorporates ergonomics. we need to think about the human interaction with the system, as well as the technical design itself, and I think that’s very important. It’s something that is very easy, especially for technical people, to miss. As engineers some of us love diving into the detail, that’s where we feel comfortable, that’s what we want to do, and then maybe we miss sometimes the big picture – somebody is actually going to use this thing and make it work. we need to think about all of our workers to make sure that they stay healthy and safe at work. We need to think about how they are going to physically interact with the system, etc. It may not be just the physical system that we’re designing, but of course, the work processes that go around it, which is important.

It is worth pointing out that in the UK I’m used to a narrow definition of ergonomics. I’m used to a definition of ergonomics that’s purely about the physical way that humans interact with the system. Can they do so safely and comfortably? Can they do repetitive tasks without getting injured? That includes anthropomorphic aspects, where we think about the variation in size of human beings, different sex’s, different races. Also, how do people fit in the machine or the vehicle or interact with it. But, the way that in Australia we talk about ergonomics is it’s a much bigger picture than that. I would say don’t just think about ergonomics, think about human factors. It’s the science of people working. let’s understand human capabilities and apply that knowledge in the design of equipment and tools and systems and ways of working that we expect the human to use. Humans are pretty clever beasts in many ways and we’re still very good at things that a lot of machines are just not very good at. we need to design stuff which compliments the human being and helps the human being to succeed, rather than just optimising technical design in isolation. And this quotation is from the ARPANSA definition because it was the best one that I could find in Australia. I will no doubt talk about human factors another time in some depth.

Responsibilities

Under the law, (this is tailored for Australian law, but a lot of this is still good principles that are applicable anyway) different groups and individuals have responsibilities for safe design. Those who manage the design and the technical stuff directly and those who make resourcing decisions. For example, we can think about building architects, industrial designers, drafts people who create the design. Individuals who make design decisions at any lifecycle phase, that could be a wide range of people and of course not just technical people, but stakeholders who make decisions about how people are employed, how people are to interact with these systems, how they are to maintain it and dispose of it, etc. And of course, work health and safety professionals themselves. there’s a wide range of stakeholders involved here potentially. Also, anybody who alters the design, and it may be that we’re talking about a physical alteration to design or maybe we’re just using a piece of kit in a different context. we’re using a machine or a process or piece of software that was designed to do X, and we’re actually using it to do Y, which is more common than you might think. if we are not putting an existing design in a different context, which was never envisaged by the original designers, we need to think about the implications of both the environment on the design and the design on the environment and the human beings mixed up working in both. There’s a lot of accidents caused by modifying bits of kit, some might call it a signature accident in the U.K.: the Flixborough Chemical Plant explosion. That was one of the things that led to the creation of Molten Health and Safety in the UK and that was caused by people modifying a design and not fully realising the implications of what they were doing. Of course, the result was a gigantic explosion and lots of dead bodies. Hopefully it won’t always be so dramatic the things that we’re looking at, but nevertheless, people do ask designs to do some weird stuff.

If we want safe design, we can get it more effectively and more efficiently when people get together who control and influence outcomes and who make these decisions so that they collaborate on building safety into the design rather than trying to add on afterwards, which in my experience never goes well. We want to get people together, think about these things up front where it’s maybe a desktop exercise or it’s a meeting somewhere. It requires some people to attend the meeting and prepare for it and so on, and we need records, but that’s cheap compared to later design stages. When we’re talking about industrial plants or something that’s going to be mass produced, making decisions later is always going to be more costly and less effective and therefore it’s going to be less popular and harder to justify. get in and do it early while you still can. There’s some good guidance on all this stuff on who is responsible.

There’s the Principles of Good Work Design Handbook, which is created by Safe Work Australia and it’s also on the Safety Artisan Website (I gained permission to reproduce that) and there’s a model Code of Practice for safe design of structures. There was going to be a model Code of Practice for the safe design of plants, but that never became a Code of Practice, that’s just guidance. Nevertheless, there is a lot of good stuff in there. And there’s the Work, Health and Safety Regulations. And incidentally, there’s also a lot of good guidance on Major Hazard Facilities available. Major Hazard Facilities are anywhere where you store large amounts of potentially dangerous chemicals. However, the safety principles that are in the guidance for the MHF is very good and is generally applicable not just for chemical safety, but for any large undertaking where you could hurt a lot of people on that. MHF guidance I believe was originally inspired by the COMAH regulations in the UK, again which came from a major industrial disaster, Piper Alpha platform in the North Sea which caught fire and killed 167 people. It was a big fire. if you’ve got an enterprise where you could see a mass casualty situation, you’ll get a lot more guidance from the MHF stuff that’s really aimed at preventing industrial sized accidents. there’s lots of good stuff available to help us.

Design for Plant

So, examples of things that we should consider. We need to, (and I don’t think this will be any great surprise to you) think about all phases of the life cycle, I think we banged on about that enough. Whether it be plant (waste plant in this case), whatever it might be, from design and manufacture or right through to disposal. Can we put the plant together? Can we erect it or what structure and we install it? Can we facilitate safe use again? Again, thinking about the physical characteristics of your users, but not just physical, think about the cognitive thinking of your users. If we’re making control system, can the users use it to practically to exploit the plant for the purpose it was meant for whilst staying safe? What can the operator actually do, what can we expect them to perform successfully and reliably time after time because we want this stuff to keep on working for a long, long time, in order to make money or to do whatever it is we want to do. And we also need to think about the environment in which the plant will be used – very important.

Some more examples. Think about intended use and reasonably foreseeable misuse. If you know that a piece of kit tends to get misused for certain things, then either design against it or give the operator a better way of doing it. A really strange example, apparently the designers of a particular assault rifle knew that the soldiers tended to use a bit of the rifle as a can opener or to do stuff like that or to open beer bottles, so they incorporated a bottle opener in the design so that the soldiers would use that rather than damage the assault rifle opening bottles of beer. A crazy example there but I think it’s memorable. we have to consider by law intended use, if you go to the W.H.S lesson, you’ll see that’s written right through the duties of everybody, reasonably foreseeable misuse I don’t think is a hard requirement in every case, but it’s still a sensible thing to do.

Think about the difficulties that workers might face doing repairs or maintenance? Again, sorry, I banged on about that, I came from a maintenance world originally, so I’m very used to those kinds of challenges. And consider what could go wrong. Again, we’re getting back into classic design safety here. Think about the failure modes of your plant. Well, ideally, we always wanted a fail-safe, but if we can’t do that, well, how can we warn people? How can we make sure we minimise the risk if something goes wrong and if a foreseeable hazard occurs? And by foreseeable, I’m not just saying, well we shut ourselves in a darkened room and we couldn’t think of anything, we need to look at real world examples of similar pieces of kit. Look at real world history, because there’s often an awful lot of learning out there that we can exploit, if only we bother to Google it or look it up in some way. As I think it was Bismarck, the great German leader said only a fool learns from his own mistakes, a wise man learns from other people’s mistakes. that’s what we try and do in safety.

Product Lifecycle

Moving onto life cycle, this is a key concept. Again, we gone on and on and on about this. We need to control risks, not just for use, but during construction and manufacture in transit, when it’s being commissioned and tested and used and operated, when it’s being repaired, maintained, cleaned or modified. And then at the end of, I say the end of life, it may not be end of life when it’s being decommissioned. maybe a decommissioning kit, moving it to a new site or maybe a new owner has bought it. we need to be able to safely take it upon move and put it back together again. And of course, by that stage, we may have lost the original packaging. we may have to think quite carefully about how we do this, or maybe we can’t fully disassemble it as we did during the original installation. maybe we’ve got to move an awkward bit of kit around. And then at the end of life, how are we going to dismantle it or demolish it? Are we going to dispose of it, or ideally recycle it? Hopefully if we haven’t built in anything too nasty or too difficult to recycle, we can do that. that would be a good thing.

It’s worth reminding ourselves, we do get a safer product that is better for downstream users if we eliminate and minimise those hazards as early as we can. as I said before, in these early phases, there’s more scope in order to design out stuff without compromising the design, without putting limitations on what it can do. Whereas often when you’re adding safety in, so often that is achieved only at a cost in terms of it limits what the users can do or maybe you can’t run the plant at full capacity or whatever it might be, which is clearly undesirable. designers must have a good understanding of the lifecycle of their kit and so do those people who will interact with it and the environment in which it’s used. Again, if you’ve listened to me talking about our system safety concepts we hammer this point about it’s not just the plant it’s what you use it for, the people who will use it and the environment in which it is used. especially for complex things, we need to take all those things into account. And it’s not a trivial exercise to do this.

Then thirdly, as we go through the product life cycle, we may discover new risks, and this does happen. People make assumptions during the concept and design phase and fair enough you must make assumptions sometimes in order to get anything done. But those assumptions don’t always turn out to be completely correct or something gets missed, we missed some aspect often. It’s the thing you didn’t anticipate that often gets you. as we go through the lifecycle, we can further improve safety if people who have control over decisions and actions that are taken incorporate health and safety considerations at every stage and actually proactively look at whether we can make things better or whether something has occurred that we didn’t anticipate and therefore that needs to be looked into. Another good principle that doesn’t always happen, we shouldn’t proceed to the next stage in the life cycle until we have completed our design reviews, we have thought about health and safety along with everything else, and those who are control have had a chance to consider everything together. And if they’re happy with it, to approve it and it moves on. it’s a very good illustration. Again, it will come as no surprise to many listeners there are a lot of projects out there that either don’t put in design reviews at all or you see design reviews being rushed. Lip service is paid to them very often because people forget the design reviews are there to review the design and to make sure it’s fit for purpose and safe and all the other good things, and we just get obsessed with getting through those design reviews, whether we’re the purchaser, whether we’re just keen to get on with the job and the schedule must be maintained at all costs. Or if you’re the supplier, you want to get through those reviews because there’s a payment milestone attached to them. there’s a lot of temptation to rush these things. Often, rushing these things just results in more trouble further downstream. I know it takes a lot of guts, particularly early in a project to say, no, we’re not ready for this design review, we need to do some more work so that we can get through this properly. That’s a big call to make, often because not a lot of people are going to like you for making that call, but it does need to.

Benefits of Safe Design

So, let’s talk about the benefits. These are not my estimates, these are Safe Work Australia’s words, so they feel that from what they’ve seen in Australia and now surveying safety performance elsewhere, I suspect as well, that building safety into a plant can save you up to 10 percent of its cost. Whether it be through, an example here is reductions in holdings of hazardous materials, reduce need for personal protective equipment, reduce need filled testing and maintenance, and that’s a that’s a good point. Very often we see large systems, large enterprises brought in to being without sufficient consideration of these things, and people think only about the capital costs of getting the kit into service. Now, if you’re spending millions or even possibly billions on a large infrastructure project, of course you will focus on the upfront costs for that infrastructure. And of course, you are focused on getting that stuff into service as soon as possible so you can start earning money to pay for the capital costs of it. But it’s also worth thinking about safety upfront. A lot of other design disciplines as well, of course, and making sure that you’re not building yourself a life cycle, a lifetime full of pain, doing maintenance and testing that, to be honest, you really don’t want to be doing, but because you didn’t design something out, you end up with no choice. And so, we can hopefully eliminate or minimise those direct costs with unsafe design, which can be considerable rework, compensation, insurance, environmental clean-up. You can be sued by the government for criminal transgressions and you can be sued by those who’ve been the relatives of the dead, the injured, the inconvenienced, those who’ve been moved off their land. And these things will impact on parties downstream, not the designers. And in fact, often but not always, just the those who bought product and used it. there’s a lot of incentive out there to minimise your liability and to get it right up front and to be able to demonstrate they got it right up front. Particularly if you’re a designer or a manufacturer and you’re worried that some of your users are maybe not as professionals and conscientious using your stuff as you would like because it’s still got your name and your company logo plastered all over it.

I don’t think there’s anything new in here. there’s many benefits or we see the direct benefits. We’ve prevented injury and disease and that’s good. Not just your own, but other peoples. We can improve usability, very often if you improve safety through improving human factors and ergonomics, you’re going to get a more usable product that people like using, it is going to be more popular. Maybe you’ll sell more. You’ll improve productivity. those who are paying for the output are happy. You’ll reduce costs, not only reduce costs, (through life I’m talking about you might have to spend a little bit more money upfront), we can actually better predict and manage operations because we’re not having so many outages due to incidents or accidents. Also, we can demonstrate compliance with legislation which will help you plug the kit in the first place, but also it is necessary if you’re going to get past a regulator or indeed if you don’t want to get sent to jail for contravening the WHS Act. And benefits, well, innovation. I have to say innovation is a double-edged sword because some places love innovation, you’ll be very popular if you innovate. Other industries hate innovation and you will not be popular if you innovate. That last bullet, I’m not so sure it’s about innovation. Safety design, I don’t necessarily think it demands new thinking, it just demands thinking. Because most things that I’ve seen that are preventable, that have gone wrong and could have been stopped, it only required a little bit of thought and a little bit of imagination and a little bit of learning from the past, not just innovating the future.

Legal Obligations

So that brings us neatly on to think about our legal obligations. In Australia, and in other countries, there will be similar obligations, work, health and safety law impose duties on lots of people from designers, manufacturers, importers, suppliers, anybody who puts the stuff together, puts it up, modifies it, disposes of it. These obligations, as it says, will vary dependent on state or territory or whether Commonwealth W.H.S applies. But if it’s WHS, it’s all based on the model WHS from SafeWork Australia, so it will be very similar. In the W.H.S lesson, I talk about what these duties are and what you must do to meet them. You will be pleased to know that the guidance in safe design is in lock step with those requirements. this is all good stuff, not because I’m saying it but because I’m actually showing you what’s come out of the statutory authority.

Yes, these obligations may vary, we talk about that quite a lot and in other sessions. Those who make decisions, and not just technical people, but those who control the finances, have duties under WHS law. Again, go and see the WHS lesson than the talks about the duties, particularly the duties of senior management officers and due diligence. And there are specific safety due diligence requirements in WHS, which are very well written, very easy to read and understand. there’s no excuse for not looking at this stuff, it is very easy to see what you’re supposed to do and how to stay on the right side of the law. And it doesn’t matter whether you’re an employer, self-employed, if you control a workplace or not, there are duties on designers upstream who will never go near the workplace that the kit is actually used in. if a client has some building or structure designed and built for leasing, they become the owner of the building and they may well retain health and safety duties for the lifetime of that building if it’s used as a workplace or to accommodate workers as well.

Recap

I just want to briefly recap on what we’ve what we’ve heard. Safe design, I would say the big lesson that I’ve learned in my career is that safe design is not just a technical activity for the designers. I’ve worked in many organisations where the pedigree, the history of the organisation was that you had. technical risks were managed over here, and human or operational risks well managed over here, and there was a great a gulf between them, they never they never interacted very much. There was a sort of handover point where they would chuck the kit over the wall to the users and say, there, get on with it, and if you have an accident, it’s your fault because you’re stupid and you didn’t understand my piece of kit. And similarly got the operator saying all those technical people, they’ve got no idea how we use the kit or what we’re trying to do here, the big picture, they give us kit that is not suitable or that we have to misuse in order to get it to do the job.

So, if you have these two teams, players separately not interacting and not cooperating, it’s a mess. And certainly, in Australia, there is very explicit requirements in the law and regulations and the whole code of practice on consultation, communication and cooperation. these two units have got to come together, these two sides of the operation have got to come together in order to make the whole thing work. And WHS law does not differentiate between different types of risk. There is just risk to people, so you cannot hide behind the fact that, well I do technical risk I don’t think about how people will use it, you’ve just broken the law. you’ve got to think about the big picture, and you know, we can’t keep going on and on in our silence. A little bit of heart to heart, but that really, I think, is the value add from all of this. The great thing about this design guidance is that it encourages you to think through life, it encourages you to think about who is going to use it and it encourages you to think about the environment. And you can quite cheaply and quite quickly, you could make some dramatic improvements in safety by thinking about these things.

I’ve met a lot of technical people, if a risk control measure isn’t technical, if it isn’t highly complicated and involves clever engineering, then some people have got a tendency to look down their nose at it. What we need to be doing is looking at how we reduce risk and what the benefits are in terms of risk reduction, and it might be a really very simple thing that seems almost trivial to a technical expert that actually delivers the safety, and that’s what we’ve got to think about not about having a clever technical solution necessarily. If we must have a clever technical solution to make it safe, well, so be it. But, we’d quite like to avoid that most of the time if we can.

Australian Approach

Just to bring this to a close. Australia in the 10 years to 2022 has got certain targets. we’ve got seven national action areas, and safe by design or safe design is one of them. As I’ve said several times, Australian legislation requires us to consult, cooperate and coordinate, so far as is reasonably practicable. And we need to work together rather than chuck problems over the wall to somebody else. You might think you delegated responsibility to somebody else, but actually if you’re an officer of the person or conducting the business or undertaking, then you cannot ditch all of your responsibilities, so you need to think very carefully about what’s being done in your name because legally it can come back to you. you can’t just assume that somebody else is doing it and will do a reasonable job, it’s your duty to ensure that it is done, that you’ve provided the resources and that it is actually happening.

And so, what we want to do, in this 10-year period, is we want to achieve a real reduction, 30% reduction in serious injuries nationwide in that 10-year period and reduce work related fatalities by at least a fifth. these are specific and valuable targets, they’re real-world targets. This is not an academic exercise, it’s about reducing the body count and the number of people who end up in a hospital, blinded or missing limbs or whatever. it’s important stuff. And as it says, SafeWork Australia and all the different regulators have been working together with industry unions and special interest groups in order to make this all happen. that’s all excellent stuff.

End: Safe Design

And it just remains for me to say that most of the text that I’ve shown you is from the Safe Work Australia website, and that’s been reproduced under license, under Creative Commons license. You can see the full details on the safetyartisan.com website. And just to point out that the words, this presentation itself are copyright of The Safety Artisan and I just realised I drafted this in 2019, it’s copyright 2020, but never mind, I started writing this in 2019.

Now, if you want more videos please subscribe to the Safety Artisan channel on YouTube.  And that is the end of the presentation, so thank you very much for listening and watching and from the safety artisan, I just say, I wish you a successful and safe 2020, goodbye.

Categories
Mil-Std-882E Safety Analysis

Sub-System Hazard Analysis

In this video lesson, The Safety Artisan looks at Sub-System Hazard Analysis, or SSHA, which is Task 204 in Mil-Std-882E. We explore Task 204’s aim, description, scope, and contracting requirements. We also provide value-adding commentary and explain the issues with SSHA – how to do it well and avoid the pitfalls.

This is the seven-minute demo, the full video is 40-minutes’ long.

Topics: Sub-System Hazard Analysis

  • Preamble: Sub-system & System HA.
  • Task 204 Purpose:
    • Verify subsystem compliance;
    • Identify (new) hazards; and
    • Recommend necessary actions.
  • Task Description (six slides);
  • Reporting;
  • Contracting; and
  • Commentary.
Transcript: Sub-System Hazard Analysis

Introduction

Hello, everyone, and welcome to the Safety Artisan, where you will find professional, pragmatic, and impartial instruction on all things system safety. I’m Simon – I’m your host for today, as always and it’s the fourth of April 22. With everything that’s going on in the world, I hope that this video finds you safe and well.

Sub-System Hazard Analysis

Let’s move straight on to what we’re going to be doing. We’re going to be talking today about subsystem hazard analysis and this is task 204 under the military standard 882E. Previously we’ve done 201, which was preliminary hazard identification, 202, which is preliminary hazard analysis, and 203, which is safety requirements hazard analysis. And with task 204 and task 205, which is system has analysis, we’re now moving into getting stuck into particular systems that we’re thinking about, whether they be physical systems or intangible. We’re thinking about the system under consideration and I’m really getting into that analysis.

Topics for this Session

So, the topics that we’re going to cover today, I’ve got a little preamble to set things in perspective. We then get into the three purposes of task 204. First, to verify compliance. Secondly, to identify new hazards. And thirdly, to recommend necessary actions. Or in fact, that would be recommend control measures for hazards and risks. We’ve got six slides of task description, a couple of slides on reporting, one on contracting, and then a few slides on some commentary where I put in my tuppence worth and I’ll hopefully add some value to the basic bones of the standard. It’s worth saying that you’ll notice that subsystem is highlighted in yellow and the reason for that is that the subsystem and system hazard analysis tasks are very, very similar. They’re identical except for certain passages and I’ve highlighted those in yellow. Normally I use a yellow highlighter to emphasize something I want to talk about. This time around, I’m using underlining for that and the yellow is showing you what these different for subsystem analysis as opposed to system. And when you’ve watched both sessions on 204 and 205, I think you’ll see the significance of why I’ve done.

Preamble – Sub-system & System HA

Before we get started, we need to explain the system model that the 882 is assuming. If we look on the left-hand side of the hexagons, we’ve got our system in the centre, which we’re considering. Maybe that interfaces with other systems. They work within operating environment; hence we have the icon of the world, and the system and maybe other systems are there for a purpose. They’re performing some task; they’re doing some function and that’s indicated by the tools. We’re using the system to do something, whatever it might be.

Then as we move to the right-hand side, the system is itself broken down into subsystems. We’ve got a couple here. We’ve got sub-system A and B and then A further broken down into A1 and A2, for example. There’s some sort of hierarchy of subsystems that are coming together and being integrated to form the overall system. That is the overall picture that I’d like to bear in mind while we’re talking about this. The assumption in the 882, is we’re going to be looking at this subsystem hierarchy bottom upwards, largely. We’ll come on to that.

System Requirements Hazard Analysis (T204)

Purpose of the task, as I’ve said before, it’s threefold. We must verify subsystem compliance with requirements. Requirements to deal with risk and hazards. We must identify previously unidentified hazards which may emerge as we’re working at a lower level now. And we must recommend actions necessary. That’s further requirements to eliminate all hazards or mitigate associated risks. We’ll keep those three things in mind and that will keep coming up.

Task Description (T204) #1

The first of six slides on the task description. Basically, we are being told to perform and document the SSHA, sub-system hazard analysis. And it’s got to include everything, whether it be new developments, COTS, GOTS, GFE, NDI, software and humans, as we’ll see later. Everything must be included. And we’re being guided to consider the performance of the subsystem: ‘What it is doing when it is doing it properly’. We’ve got to consider performance degradation, functional failures, timing errors, design errors or defects, and inadvertent functioning – we’ll come back to that later. And while we’re doing analysis, we must consider the human as a component within the subsystem dealing with inputs and making outputs. If, of course, there is an associated human. We’ve got to include everything, and we’ve got to think about what could go wrong with the system.

Task Description (T204) #2

The minimum that the analysis has got to cover is as follows. We’ve got to verify subsystem compliance with requirements and that is to say, requirements to eliminate hazards or reduce risks. The first thing to note about that is you can’t verify compliance with requirements if there are no requirements. if you haven’t set any requirements on the subsystem provider or whoever is doing the analysis, then there’s nothing to comply with and you’ve got no leverage if the subsystem turns out to be dangerous. I often see it as it gets missed. People don’t do their top-down systems engineering properly; They don’t think through the requirements that they need; and, especially, they don’t do the preliminary hazard identification and analysis that they need to do. They don’t do Task 203, the SRHA, to think about what requirements they need to place further down the food chain, down the supply chain. And if you haven’t done that work, then you can’t be surprised if you get something back that’s not very good, or you can’t verify that it’s safe. Unfortunately, I see that happen often, even on exceptionally large projects. If you don’t ask, you don’t get, basically.

We’ve got two sub-paragraphs here that are unique to this task. First, we’ve got to validate flow down of design requirements. “Are these design requirements valid?”, “Are they the right requirements?” From the top-level spec down to more detailed design specifications for the subsystem. Again, if you haven’t specified anything, then you’ve got no leverage. Which is not to say that you have to dive into massive detail and tell the designer how to do their job, but you’ve got to set out what you want from them in terms of the product and what kind of process evidence you want associated with that product.

And then the second sub-paragraph, you’ve got to ensure design criteria in the subsystem specs have been satisfied. We need to verify that they’re satisfied, and that V and V of subsystem mitigation measures or risk controls have been included in test plans and procedures. As always, the Mil. standard 882 is the American standard, and they tend to go big on testing. Where it says test plans and procedures that might be anything – you might have been doing V and V by analysis, by demonstration, by testing, by other means. It’s not necessarily just testing, but that’s often the assumption.

Task Description (T204) #3

We must also identify previously unidentified hazards because we are now down at a low level of detail in a subsystem and stuff probably will emerge at that level that wasn’t available before. First, number one, we’ve got to ensure the implementation of subsystem design requirements and controls. And ensure that those requirements and controls have not introduced any new hazards, because very often accidents occur. Not because the system has gone wrong – the system is working as advertised – but the hazards with normal operation maybe just weren’t appreciated and guarded against or we just didn’t warn the operators that something might happen that they needed to look out for. A common shortfall, I’m afraid.

And number two, we’ve got to determine modes of failure down to component failure and human errors, single points of failure, common-mode failures, effects when failures occur in components, and from functional relationships. “What happens if something goes wrong over on this side of the system or subsystem and something else is happening over here?” What are those combinations? What could result? And again, we’ve got to consider hardware and software, including all non-developmental type stuff, and faults, and occurrences. Again, I see very often, buyers/purchases don’t think about the off the shelf stuff in advance or don’t include it. And then sometimes also you see contractors going “This is off the shelf, so we’re not analysing it.” Well, the standard requires that they do analyse it to the extent practicable. And they’ve got to look at what might go wrong with all of this non-development to stuff and integrate the possible effects and consider. That’s another common gotcha, I’m afraid. we do need to think about everything, whether it’s developmental or not.

Task Description (T204) #4

And then part C, recommending actions necessary to eliminate hazards if we can. Very often we can’t, of course, and we have to mitigate. We must reduce or minimize the associated risk of those hazards. In terms of the harm that might come to people. We’ve got to ensure that system-level hazards, it says attributed. Maybe we believe when we did the earlier analysis that the subsystem could contribute to a higher-level hazard, or maybe we’ve allocated some failure budget to this particular subsystem, which it has got to keep to if we’re going to meet the higher-level targets. You can imagine lots of these subsystems all feeding up a certain failure rate and different failure modes. And overall, when you pull it all together, we may have to meet some target or reduce the number of failures in their propagation upwards in order to manage hazards and risks. We’ve got to make sure that we’ve got adequate mitigation controls of these potential hazards are implemented in the design.

If we think back to the hierarchy, we prefer to fix things in the design, eliminate the hazard if possible, or make changes to the design to eliminate or reduce the hazard, rather than just rely on human beings to catch the problem and deal with it further downstream. It’s far more effective and cheaper, in the long run, to fix things in design they are more effective controls. Certainly, in this standard in Australian law, and in the UK and elsewhere, you will find either regulations or law or codes of practice or recognized and accepted good practice that says, “You should do this”. It’s a very, very common requirement and we should pretty much assume that we have to do this.

Task Description (T204) #5

Interesting clause here in 2.2, it says if no specific hazard analysis techniques are directed or the contractor wants to take a different route to what is directed, then they’ve got to obtain approval from the program manager. If the PM (Project Manager) hasn’t specified analysis techniques, and they may not wish to, they may just wish to say you’ll do whatever analysis is required in order to identify hazards and mitigate them. But in many industries, there are certain ways of doing things and I’ve said before in previous lessons, if you don’t specify that you want something, then contractors will very often cut the safety program to the bone in order to be the cheapest bid. the customer will get what they prioritize. If the customer prioritizes a cheap bid and doesn’t specify what they want, then they will get the bare minimum that the contractor thinks they can get away with. If you don’t ask, you don’t get – Becoming a theme that isn’t it?

Task Description (T204) #6

Let’s move on to 2.3. Returning to software, we’ve got to include that. The software might be developed separately, but nevertheless, the contractor performing the SSHA shall monitor the software development, shall obtain data from each phase of the software development process in order to evaluate the contribution of the software to the subsystem hazard analysis. There’s no excuse for just ignoring the software and treating it as a black box. Of course, very often these days the software is already developed. It’s a GFE or NDI item, but there still should be evidence available or you do a black-box analysis of the subsystem that the software is sitting in. Again, if the software developer reports any identified hazards, they’ve got to be reported to the program manager in order to request appropriate direction.

This assumes a level of interaction between the software developers right up the chain to the program manager. Again, this won’t happen unless the program manager directs it and pays for it. If the PM doesn’t want to pay for it, then they are either going to have to take a risk on not knowing about the functionality of the software that’s hidden within the subsystem. Or they’re going to deal with it some other way, which is often not effective. The PM needs to do a lot of work upfront in order to think what kind of problems there might be associated with a typical subsystem of whatever kind it is we’re dealing with. And think about “How would I deal with the associated risks?” “What’s the best way to deal with them in the circumstances?” If I’m buying stuff off the shelf and I’m not going to get access to hazard analysis or other kinds of evidence, how am I going to deal with them? Big questions.

And then 2.4, the contractor shall update the SSHA following changes, including software design changes. Again, we can’t just ignore those things.  That’s slide six out of six. Let’s move on to reporting.

Reporting (T204) #1

The first slide, contractor’s got to prepare a report that contains results from the task, including within the system description, physical and functional characteristics of the system, a list of the subsystems, and a detailed description of the subsystem being analysed, including its boundaries. And from other videos, you’ll know how much and how often I emphasize knowing where the boundaries are because you can’t really do effective safety analysis and safety management on an unbounded system. It just doesn’t work. There’s a requirement here for quite a lot of information reference to more detailed descriptions as they become available. The standard says they shall be supplied. That’s a lot of information that probably texts and pictures of all sorts of stuff and that’s going to need to go into a report. And typically, we would expect to see a hazard analysis report or a HAR with this kind of information in it. Again, if the PM/customer doesn’t specify that HAR, then they’re not going to get it and they’re not going to get textual information that they need to manage the overall system.

Reporting (T204) #2

So, if we move on to parts B and C of the reporting requirement. We’ve got to describe hazard analysis methods and techniques, provide a description of each method and the technique used, and a description of the assumptions made. And it says for each qualitative or quantitative data. This is another area that often gets missed. If you don’t know what techniques have been used and you don’t know the assumptions that almost certainly that subsystem analyser will have to make because they probably don’t have visibility in the rest of the system. If you don’t have that information, it becomes very difficult to verify the hazard analysis work and to have confidence in it.

And the hazard analysis results. Content and format vary. Something else the PM is going to think about and specify upfront. Then results should be captured the hazard tracking system. Now, usually, this hazard tracking system is hazard log. It might be a database, a spreadsheet or even a word document, or something like that. And usually, in the hazard tracking system, we have the leading particulars. We don’t always have, in fact, we shouldn’t have, every little piece of information in the hazard tracking system because it will quickly become unwieldy. Really, we want the hazard log to have the leading particulars of all the hazards, causes, consequences and controls. And then the hazard log should refer out to that hazard analysis report or other reports and data, whatever they’re called, other records.

If we go back up, this reemphasizes the kind of detail that’s here in 2.5 A. That really shouldn’t be going in the hazard log. That should be going in a separate report which the hazard log/the hazard tracking system refers to. Otherwise, it all gets that unwieldy.

Contracting

I’ve said repeatedly the PM needs to think about this and ask for that.

Contracting; The standard assumes that the information in A to H below is specified way up front in the request for proposal. That’s not always possible to do in full detail, but nevertheless, you’ve got to think about these things really early and include them in the contractual documentation. And again, if your if you’re running a competition, by the time you get to the final RFP, you need to make sure that you’re asking for what you really need. maybe run a preliminary expression of interest or pre-competition exercise in order to tease out, detect. We’ve got to impose task 204 (A.) as a requirement. We may have to specify which people we want to involve, which functional specialists, which discipline specialists (B.). We want to get involved to address this work. Identification of subsystems to be analysed (C.). Well, if you don’t know what the design is upfront, we can’t always do that, but you could say all.

You may specify desired analysis methodologies and techniques (D.). And again, that’s largely domain dependent. We tend to do safety in certain ways in different worlds, in the air world is done in a particular way. in the maritime world, it’s a different way. With Road or Off-Road Vehicle, it’s done in a particular way, etc, etc., whatever it might be. Chemical plant, whatever. If they’re known hazards, hazardous areas or other specific items be examined or excluded (E.) because they’re covered adequately elsewhere. The PM or the client has got to provide technical data on all those non-development developmental items (F.), particularly if they’re specifying that the contractor will use them. If the client says “You will use this. You will use these tires, therefore, this data with these tires” or whatever it might be, you’re going to – we want a system that’s going to use to standardized spares of standardized fuel or whatever it might be or is maintainable by technicians and mechanics with these standard skill sets. There may be all sorts of reasons for asking or forcing contracts to do certain things, in which case the purchaser is responsible for providing that data.

And again, many purchases forget to do that entirely or do it very badly, and then that can cripple a safety program. What’s the concept of operations (G.). What are we going to do with this stuff? What’s the context? What’s the big picture? That’s important. And any other specific requirements (H.). What risk matrix? What risk definitions are we using on this program? Again, important otherwise, different contractors do their own thing, or they do nothing at all. And then the client must pick up pieces afterwards, which is always time-consuming and expensive and painful. And it tends to happen at the back of a program when you’re under time pressure anyway. It’s never a happy place to be. do make sure that clients and purchases that you’ve done your homework and specified this stuff upfront, even if it turns out to be not the best thing you could have specified, it’s better to have an 80 percent solution that’s pretty standard and locked down.

Commentary #1

That’s the wording that’s in the task with some commentary by myself. Now some additional commentary. It says right up front, areas to consider include performance, performance degradation, functional failures, timing errors, design errors or defects and inadvertent function. What we have here basically is a causal analysis, there will be some simple techniques that you can use to identify this kind of stuff. Something like a functional failure analysis or a failure modes effects analysis, which is like an FFA, but an FMEA requires design to work on. And, FMEA, a variant of FME is FMECA, where we include the criticality of the failure as it possibly propagates out the hierarchy of the system.

These sorts of techniques will think about what could go wrong, no function when required, inadvertent function – the subsystem functions when it’s not supposed to – and incorrect function, and there’s often multiple versions of incorrect function. considering all of those causes, all of those failure modes and if we’re doing a big safety program on something quite critical, very often the those identified faults and failures and failure modes will feed into the bottom of a fault tree where we have a hierarchical build-up of causation and we look at how redundancy and mitigation and control measures mitigate those low-level failures and hopefully prevent them from becoming full-blown incidents and accidents.

And these techniques, particularly the FFA in the FMEA, are also good for hazard identification and for investigating performance and non-compliance issues. you can apply an FFA and FMEA those type of techniques to a specification and say “We’ve asked for this. What could happen if we get what we ask for?” What could go wrong? And, what could go wrong with these requirements?

Commentary #2

Now, the second part that I’ve chosen to highlight a consideration of the human within a subsystem and this is important. Traditionally, it’s not always been done that well. Human factors, I’m glad to say is becoming more prominent and more used both because in many, many systems, human is a key component, is a key player in the overall system. And in the past, we have tended to build systems and then just expect the human operator and maintainer to cope with the vicissitudes of that system. maybe the system isn’t that well designed in terms of it is not very usable, its performance depends on being lovingly looked after and tweaked and maybe systems are vulnerable to human error, and even induce human error. We need to get a lot better at designing systems for human use.

So, we could use several techniques. We could use a HAZOP, a hazard analysis operability study to consider information flows to and from the human. There are lots of specialist human factors analyses out there. And I’m hoping to run a series of human factors sessions, interviewing a very knowledgeable colleague of mine but more on that later. that will come in due course. We’ll look at those specialist human analysis techniques. But there’s been a couple of conceptual models around for quite a long time, about 20 years now at least, for how to think about humans in the system.

Human-System Models

So, we’ve got a 5M model and the SHELL model. I’m just going to briefly illustrate those. Now, both models are taken from the US Federal Aviation Authority System Safety Handbook, which dates to the end of 2000. These have been around a long time and they were around before the year 2000, and they’re quite long in the tooth.

We’ve got the SHELL model, which considers our software, hardware, environments and live-ware – the human. And there’s quite a nice checklist on Wikipedia for things to consider. We’re considering all the different interfaces between those different elements. That’s at the hyperlink you can see at the bottom of the slide.

Then on the right-hand side, we’ve got the 5M model and apologies for the gendered language. Where the five Ms are the man/the human, the machine, management, the media – and the media is the environment for operating and maintenance environment – and then in the middle is the mission. the humans, the machines, the systems, and the management come together in order to perform a mission within a certain environment. that’s another very useful way of conceptualizing our contribution of humans and interaction between human and system. Human operators usually are maintainers, frontline staff, and management, all in a particular operating environment and environmental context and how they come together to accomplish the mission or the function of the system, whatever it might be.

Now a word of caution, on this. It’s very possible to spend gigantic sums of money on human analysis. very often we tend to target it at the most critical points and we very often target it at the operator, particularly for those phases of operation where the operator must do things in a limited amount time. the operator will be under pressure and if they don’t take the right action within a certain time, something could go wrong. we do tend to target this analysis in those areas and tend to spend money hopefully in a sensible and targeted way.

Commentary #3

My final slide on the additional commentary. The other things we’ve talked about for this task, compliance checking. We should get a subsystem specification. If we don’t get a subsystem specification, well, what are the expectations on the subsystem? Are they documented anywhere? Is it in the consent to box? Is there an interface requirement document or are there interface control documents for other systems that or subsystems that interface with our subsystem – anywhere where we can get information. if we have a subsystem spec, a bunch of functional requirements say, early on we could do a functional failure analysis of those functional requirements. we can do this work really quite early if we need to and think about, “Well, what interfaces are expected or required from our subsystem?” versus “What is our subsystem actually do?” any mismatches that could give rise to problems.

So, this is a type of activity where we’re looking for continuity and we’re looking for coherence across the interface. And we’re looking for things to join up. And if they don’t join up or they’re mismatched, then there’s a potential problem. And, as we look down into the subsystem, are there any derived safety requirements from above that says this subsystem needs to do this or not do that in order to manage a hazard? Those are important to identify.

Again, if it’s not been done probably the subsystem contractor won’t do it because it’s extra expense. And they may well truly believe that they don’t need to. We’re all proud of the things that we do, and we feel sometimes emotionally threatened if somebody suggests a piece of kit might go wrong and it does blind people to potential problems.

If going the other way, we are a higher-level authority where a system prime contractor or something and we’ve got to look at the documentation from a subsystem supplier. Well, we might find out some information from sales brochures or feature lists, or there might be a description of the benefits or the functions of the system with its outputs. We hopefully should be able to get hold of some operating and maintenance manuals. And very often those manuals will contain warnings and cautions and say, “You must look after the piece of cake by doing this”. I’m thinking the gremlins now “Don’t feed it after midnight or get it wet” otherwise bad things will happen. Sorry about that, slightly fatuous example, but a good illustration, I think. And ideally, if there’s any training materials associated with the piece of kit, is there a training needs analysis that shows how the training was developed? It’s very often in a TNA if it’s done well, there’s lots of good information in there. Even if it’s not quite for the same application that weighs in the piece of kit for, you could learn a lot from that kind of stuff

And finally, if all else fails, if you’ve got a legacy piece of kit, then you can physically inspect it. And if you can take it apart, put it back together again – do so. You might discover there’s asbestos in it. You might discover that lithium batteries or whatever it might be, fire hazards, flammable materials, toxic materials, you name it. there’s a lot of ways that we can get information about the subsystem. Ideally, we ask for everything upfront. Say, you know, if there’s any hazardous chemicals in there, then you must provide the hazard sheets and the hazard data in accordance with international or national standards and so on and so forth. But if you can’t get that or you haven’t asked for it, there are other ways of doing it, but they’re often time-consuming and not the optimal way of doing it.

So again, do think about what you need upfront and do ask for it. And if the contractor can’t supply exactly what you want, what you need, you then have to decide whether you could live with that, whether you could use some of these alternative techniques or whether you just have to say, “No, thanks. I’ll go to another supplier of something similar”. And I may have to pay more for it, but I’ll get a better-quality product that actually comes with some safety evidence that means I can actually integrate it and use it within my system. Sometimes you do have to make some tough decisions and the earlier we do those tough decisions the better, in my experience.

Copyright Statement

So that’s all the technical content. Just to say that all the text that’s in italics and in speech marks is from the standard, which is copyright free. But this presentation, and especially all the commentary and the added value, is copyright at the Safety Artisan 2020.

For More …

And if you want more videos like this, rest in the 882 series and other resources on safety topics, you can find them at the website www.safetyartisan.com. And you can also go to the safety artisan page at Patreon. that’s www.pateron.com and search for Safety Artisan – all one word.

End

So, that’s the end of the presentation and it just remains for me to say, thanks very much for watching and supporting the Safety Artisan. And I’ll be doing Task 205 system hazard analysis next in the series, look forward to seeing you again soon. Bye-bye, everyone.

End: Sub-System Hazard Analysis

You can find a free pdf of the System Safety Engineering Standard, Mil-Std-882E, here.

Categories
Work Health and Safety

Guide to the WHS Act

This Guide to the WHS Act covers many topics of interest to system safety and design safety specialists, this full-length video explains the Federal Australian Work Health and Safety (WHS) Act (latest version, as of 14 Nov 2020). Brought to you by The Safety Artisan: professional, pragmatic, and impartial.

This is the four-minute demo of the full, 44-minute-long video.

Recap: In the Short Video…

which is here, we looked at:

  • The Primary Duty of Care; and
  • Duties of Designers.

Topics: Guide to the WHS Act

In this full video we will look at much more…

  • § 3, Object [of the Act];
  • § 4-8, Definitions;
  • § 12A, Exclusions;
  • § 18, Reasonably Practicable;
  • § 19, Primary Duty of Care;
  • § 22-26, Duties of Designers, Manufacturers, Importers, Suppliers & those who Install/Construct/Commission;
  • § 27, Officers & Due Diligence;
  • § 46-49, Consult, Cooperate & Coordinate;
  • § 152, Function of the Regulator; and
  • § 274-276, WHS Regulations and CoP.

Transcript: Guide to the WHS Act

Click here for the Transcript

Hi everyone and welcome to the Safety Artisan where you will find instructional videos like this one with professional, pragmatic and impartial advice which we hope you enjoy. I’m Simon and I’m recording this on the 13th of October 2019. So today we’re going to be talking about the Australian Federal Work Health and Safety Act and call it an unofficial guide or system or design safety practitioners whatever you want to call yourselves because I’m looking at the WHS Act from the point of view of system safety and design safety.

 As opposed to managing the workplace although it does that as well. Few days ago, I recorded a short video version of this and in the short video we looked at the primary duty of care and the duty particularly we look at the duty of designs. And so, we spent some time looking at that and that video is available on the freight on petrol on the safety artisan page at Patreon.com. It’s available at safetyartisan.com and you can watch it on YouTube. So just search for safety artisan on YouTube.

Topics

So, in this video, we’re going to look at much more than that. I say selected topics we’re not going to look at everything in the WHS Act as you can see there are several hundred sections of it. We’ll be here all day. So, what we’re going to look at are things that are relevant to systems safety to design safety. So, we look very briefly at the object of the act, at what it’s trying to achieve. Just one slight of definitions because there’s a lot of exclusions because the Act doesn’t apply to everything in Australia.

 We’re going to look at the Big Three involved. So really the three principles that will help us understand what the act is trying to achieve is:

  • what is reasonably practicable. That phrase that I’ve used several times before.
  • What is the primary duty of care so that sections 18 and 19. And if we jump to
  • Section 27 What are or who are officers and what does due diligence mean in a WHS setting?

So, if I step back one section 22 to 26 you know the duties of various people in the supply chain.  We cover that in the short session. So, go ahead and look at that and then moving on. There are requirements for duty holders to consult cooperate and coordinate and then a brief mention of the function of the regulator. And finally, the WHS Act enables WHS regulations and codes of practice. So we’re just mentioned that so those are the topics we’re going to cover quite a lot to get through. So that’s critical.

Disclaimer

So, first this is a disclaimer from the website from the federal legislation site and it does remind people looking at the site that the information put up there is for the benefit of the public and it’s free of charge.

 So, when you’re looking at this stuff you need to look at the relevance of the material for your purposes. OK, I’m looking at the Web site it is not a substitute for getting legal or appropriate professional advice relevant to your particular circumstances. So quick disclaimer there. This is just a way a website with general advice I think we’ll get we’ll get them and hence this video is only as good as the content that’s being present okay.

The Object of the Act

So, the object of the act then as you can say I’m quoting from it because I’m using quotation marks, so the main object of the act is to provide a balanced and nationally consistent framework for the health and safety of workers and workplaces.

 And that’s important in Australia because Australia is a federated state. So, we’ve got states and territories and we’ve got the federal government or the Commonwealth as it’s usually known and the laws all those different bodies do not always line up. In fact, sometimes it seems like the state and territories delight in doing things that are different from each other and different from the Commonwealth. And that’s not particularly helpful if you’re trying to you know operate in Australia as a corporation or you know you’re trying to do something big and trying to invest in the country.

 So, the WHS act of a model WHS Act was introduced to try and harmonize all this stuff. And you’ll see some more about that on the website. By the way and I’ve missed out on some objectives. As you can see, I’m not doing one subset B to H go to have a look at it online. But then in Section 2 The reminder is the principle of giving the highest level of protection against harm to workers and other persons as is reasonably practicable. Wonderful phrase again which will come back to okay.

Definitions

 Now there are lots of definitions in the act. And it’s worth having a look at them particularly if you look at the session that I did on system safety concepts, I was using definitions from the UK standard. Now I did that for a reason because that set of definitions was very well put together. So it was ideal for explaining those fundamental concepts where the concepts in Australia WHS are very different so if you are operating in Australian jurisdiction or you want to sell into an Australian jurisdiction do look at those definitions and actually being aware of what the definitions are will actually save you a lot of hassle in the long run.

 Now because we’re interested systems safety practitioners of introducing complex systems into service. I’ve got the definitions here of plant structure and substance. So basically, plant is any machinery equipment appliance container implement or to any component of those things and anything fitted or connected to any of those things. So, they go going for pretty a pretty broad definition. But bearing in mind we’re talking about plants we’re not talking about consumer goods. We’re not talking about selling toasters or electric toothbrushes to people. OK. There’s other legislation that covers consumer goods.

 Then when it comes to structure again, we’ve got anything that is constructed be fixed or movable temporary or permanent. And it might include things on the ground towers and masks underground pipelines infrastructure tunnels and mining any components or parts thereof. Again, a very broad definition and similarly substance any natural or artificial substance in whatever form it might be. So again, very broad and as you might recall from the previous session a lot of the rules for designers’ manufacturers, importers and suppliers cover plant structure and substances. So hence that’s why I picked just those three definitions out of the dozens there.

Exclusions

 It’s worth mentioning briefly exclusions: what the Act does not apply to. So, first, the Act does not apply to commercial ships basically. So, in Australia, the Federal legislation covering the safety of people in the commercial maritime industry is the Occupational Health and Safety Act (Maritime Industry) 1993, which is usually known as “OSHMI” applies to commercial vessels, so WHS does not. And the second exclusion is if you are operating an offshore petroleum or greenhouse gas storage platform and I think it’s more than three nautical miles offshore.

 But don’t take my word for that if you’re in that business go and check with the regulator NOPSEMA then this act the Offshore Petroleum and Greenhouse Gas Storage Act 2006 applies or OPGGS for short. So, if you’re in the offshore oil industry then you’ve got a separate Commonwealth act plot but those are the only two exceptions. So, where Commonwealth law applies the only things that WHS. does not apply to is commercial ships and offshore platforms I mentioned state and territory vs. Commonwealth. All the states and territories have adopted the model WHS system except Victoria which so far seems to be showing no interest in adopting WHS.

 Thanks, Victoria, for that. That’s very helpful! Western Australia is currently in process of consultation to adopt WHS, but they’ve still got their current OH&S legislation. So just note that there are some exclusions there. OK so if you’re in those jurisdictions then WHS does not apply. And of course, there are many other pieces of legislation and regulation that cover particular kinds of risk in Australia. For example, there’s a separate act called ARPANS that covers ionizing a non-ionizing radiation.

There are many other acts that cover safety and environmental things. Let’s go back one when I’m talking about those specific acts. They only apply to specific things whereas WHS act is a general Act applies to everything except those things that it doesn’t like to write move on.

So Far As is Reasonably Practicable

Okay now here we come to one of these three big ticket items and I’ve got two slides here. So, in this definition of reasonably practicable when it comes to ensuring health and safety reasonably practicable means doing what you are reasonably able to do to achieve the high standards of health safety in place.

 Considering and weighing up all the relevant matters; including, say, the first two we need to think about the likelihood of a hazard or risk. How likely is this thing to occur this potential threat to human health? And what’s the degree of harm that might result from the hazard or risk. So, we’ve got a likelihood and degree of harm or severity. So, if we recall the fundamental definition of risk is that it’s though it’s the factor of those two things taken together. So, this first part we’re thinking about what is the risk?

 And it’s worth mentioning that hazard is not defined in the Act and risk is very loosely defined. So, the act is being deliberately very broad here. We’re not taking a position on or style of approach to describing risks, so to the second part.

Having thought about the risk now we should consider what the person PCBU or officer, whoever it might be, ought reasonably to know about the hazard or risk and the ways of eliminating or minimizing the risks. So, what we should know about the risk and the ways of dealing with it of mitigating it of controlling and then we’ve got some more detail on these ways of controlling the risk.

 We need to think about the availability and suitability of ways to eliminate or minimize the risk. Now I’m probably going to do a separate session on reasonably practicable because there is a whole guidebook on how to do it. So, we’ll go through that and at some stage in the future and go through that step by step about how you determine availability and suitability et cetera. And so, once you get into it it’s not too difficult. You just need to follow the guidelines which are very clear and very well laid out.

 So having done all of those things, after assessing the extent of the risk and the available ways of controlling it the we can then think about the cost associated with those risk controls and whether the cost of those controls is grossly disproportionate to the risk. As we will see later, in the special session, if the cost is grossly disproportionate to the risk reduction then it’s probably not reasonable to do it. So, you don’t necessarily have to do it but we will step back and just look at the whole thing.

So, in a and b we’re looking at the likelihood and severity of the risk so and we’re (quantifying or qualitatively) assessing the risk. We’re thinking about what we could do about it, how available and suitable are those risk controls, and then putting it all together. How much will it cost to implement those risk controls and how reasonably practicable to do so. So what we have here is basically a risk assessment process that leads us to a decision about which controls we need to implement in order to achieve that ‘reasonably practicable’ statement that you see in so many parts of the act and indeed it’s also in the definition itself.

 So, this is how we determine what is reasonably practicable. We follow a risk assessment process. There is a risk assessment Code of Practice, which I will do a separate session on, which gives you a basic minimum risk assessment process to follow that will enable us to decide what is reasonably practicable. Okay, quite a big topic there. And as I say we’ll come back and do a couple more sessions on how to determine reasonably practical, so moving on to the primary duty of care we covered in the short session.

The Primary Duty of Care

 So I’m not really going to go through this again [in detail] but basically our primary duty is to ensure so far as is reasonably practicable the health and safety of workers, whether we’ve engaged them whether we’ve got somebody else to engage them or whether we are influencing or directing people carrying out the work. We have a primary duty of care if we’re doing any of those things. And secondly, it’s worth mentioning that the person conducting a business or undertaking the PCBU must ensure the health and safety of other people. Say, visitors to the workplace are members of the public who happen to be near the workplace.

 And of course, bearing in mind that this law applies to things like trains and aircraft if you have an accident with your moving vehicle or your plant you could put people in danger – in the case of aeroplanes anywhere in Australia and beyond. So, it’s not just about the work, the workers in the workplace. With some systems, you’ve got a very onerous responsibility to protect the public depending on what you’re doing. Now for a little bit more detail that we didn’t have in the short session. When we say we must ensure health and safety we’re talking about the provision and maintenance of a safe work environment or safe plant structures or safe systems of work talking about safe use handling and storage of structures and substances.

 We’re talking about adequate facilities for workers that are talking about the provision of information, training, instruction or supervision. Those workers and finally the health of workers and conditions of the workplace are monitored if need be for the purpose of preventing illness or injury. So, there should be some general monitoring of health and safety-related incidents. And if you’re dealing with certain chemicals or are you intentionally exposing people to certain things you may have to conduct special monitoring looking for contamination or poisoning of those people whatever it may be. So, you’ve got quite a bit of detail there about what it means to carry out the primary duty of care.

 And this is all consistent with the duties that we’ve talked about on designers, manufacturers, importers, and suppliers and for all these things there are codes of practice giving guidance on how to do these things. So, this whole work health and safety system is well thought through, put together, in that the law says you’ve got to do this. And there are regulations and codes of practice giving you more information on how you can fulfil your primary directive and indeed how you must fulfill your primary duty.

 And then finally there’s a slightly unusual part for at the end and this covers the special case where workers need to occupy accommodation under the control of the PCBU in order to get the job done. So you could imagine if you need workers to live somewhere remote and you provided accommodation then there are requirements for the employer to take care of those workers and maintain those premises so that they not exposed to risks.

 That’s a big deal because she might have a remote plant, especially in Australia which is a big place and not very well populated. You might be a long way away from external help. So if you have an emergency on-site you’re going to have to provide everything (not just an emergency you need to do that anyway) but if you’ve got workers living remotely as often happens in Australia you’ve got to look after those workers in a potentially very harsh environment.

And then finally it’s worth mentioning that self-employed persons have got to take care of their own health and safety. Note that a self-employed person is a PCBU, so even self-employed people have a duty of care as a PCBU.

The Three Duties

OK, sections 22 to 26. Take that primary duty of care and elaborate it for designers and manufacturers, importers and suppliers and for those installing constructing or commissioning plant substances and structures. And as we said in the free session all of those roles all of the people BCBS is doing that have three duties they have to ensure safety in a workplace and that includes you know designing and manufacturing the thing and ensuring that it’s safe and meets Australian regulations and obligations.

 We have a duty to test which actually includes doing all the calculations analysis and examination that’s needed to demonstrate safety and then to provide needed information to everybody who might use or come into contact with the system so those three duties apply consistently across the whole supply chain. Now we spent some time talking about that. We’re going to move on OK, so we are halfway through. So, a lot to take in. I hope you’re finding this useful and enjoying this. Let’s move on. Now this is an interesting one.

Officers of the PCBU

Officers of the PCBU have additional duties and an officer of the PCBU might be a company director. That’s explicitly included in the definition. A senior manager somebody who has influence. Offices of the PCBU must exercise due diligence. So basically, the implied relationship is you’ve got a PCBU, you’ve got somebody directing work whether it be design work manufacturing operating a piece of kit whatever it might be. And then there are more senior people who are in turn directing those PCBUs (the officers) so the officers must exercise due diligence to ensure that the PCBUs comply with their duties and obligations.

Sections 2 to 4 cover penalties for offices if they fail. I’m not going to discuss that because as I’ve said elsewhere on the Safety Artisan website, I don’t like threatening people with penalties because I actually think that results in poor behavior, it actually results in people shirking and avoiding their duties rather than embracing them and getting on with it. If you frighten people or tell them what’s going to happen to them, they get it wrong. So, I’m not going to go there. If you’re interested you can look up the penalties for various people, which are clearly laid out. We move on to Section 5.

Due Diligence

 We’re now talking about what is due diligence in the context of health and safety. OK, I need to be precise because the term due diligence appears in other Australian law in various places meaning various things, but here this is the definition of due diligence within the WHS context. So, we’ve got six things to do in order to demonstrate due diligence.

So, officers must acquire and keep up to date with knowledge of work health and safety matters obligations and so forth. Secondly, officers must gain an understanding of the nature of the operations of the piece and risks they control.  So, if you’re a company director you need to know something about what the operation does. You cannot hide behind “I didn’t know” because it’s a legal requirement for you to do it. So that closes off a whole bunch of defenses in court. You can’t plead ignorance because ignorance is, in fact, illegal and you’ve got to have a general understanding of the hazards and risks associated with those operations. So, you don’t necessarily have to be up on all the specifics of everything going on in your organization but whatever it is that your organization does. You should be aware of the general costs and risks associated with that kind of business.

Now, thirdly, we are moving on basically C D E and F refer to appropriate resources and processes, so the officers have got to ensure that PCBUs have available and use appropriate resources and processes in order to control risks. OK so that says you’ve got to provide those resources and processes and there is supervision, or some kind of process or requirement to say, yep, we put in let’s say a safety management system that ensures people do actually use the stuff that they are supposed to use in order to keep themselves safe.

 And that’s very relevant of course because often people don’t like wearing, for example, protective personal protective equipment because it’s uncomfortable or slows you down, so the temptation is to take it off. Moving on to part D we’re still on the appropriate processes; we must have appropriate processes for receiving and considering information on incidents, hazards and risks. So again, we’ve got to have something in place that keeps us up to date with the incidents, hazards and risks in our own plants and maybe similar plants in the industry and, we need a process to respond in a timely way to that information.

 So, if we discover that there is a new incident or hazard that you didn’t previously know about. We need to respond and react to that quickly enough to make a difference to the health and safety of workers. So again as another that sort of works in concert with part B doesn’t it. In part A and B we need to keep up to date on the risks and what’s going on in the business and part A, we need to ensure that the PCBU has processes for compliance with any duty or obligation and follows them again to provide that stuff.

In the system safety world, often the designers will need to provide the raw material that becomes those processes. Or maybe if we’re selling the product, we sell a product with the instruction manual with all the processes that could be required.

And then finally the officers must verify the provision and use of these resources and processes that we’ve been talking about in C D an E. So, we’ve got a simple six-point program that comprises due diligence, but as you can see it’s very to the point and it’s quite demanding. There’s no shirking this stuff or pretending you didn’t know and it’s I suspect it’s designed to hang Company directors who neglect and abuse their workers and, as a result, harm happens to them.

But I mean ultimately let’s face it this is all good common-sense stuff. We should be doing this anyway. And in any kind of high-risk industry we should have a safety management system that does all of this and more. These are only the minimum required for all industries and all undertakings in Australia. OK let’s move away from the big stick. Let’s talk about some sort of cozy, softer stuff.

Consult, Cooperate and Coordinate

If you are a duty holder, if you’ve got a duty of care to people as a PCBU or an officer, you must consult, cooperate and coordinate your activities with all other offices and bases be used.

You have a duty in relation to the same matter. So perhaps you are a supplier of kit and you get information from the designer or the manufacturer with the updates on safety or maybe they inform you of problems with the kit. You must pass that on. Let’s imagine you’re introducing a complex system into service. There are going to be lots of different stakeholders, and you all must work together in order to meet WHS obligations. So, there’s no excuse or trying to ask the buck to other people.

That’s not going to work if you haven’t actively managed the risk, as you are potentially already doing something illegal and again, we won’t talk about the penalties of this. We’re just talking about the good things we’re expected to do. So, we’re trying to keep it positive. And you’ve got a duty to consult with your workers who either carry out work or who are likely to be directly affected by what’s going on and the risks. Now, this is a requirement that procedures in Sections 2 and 3, but of course we should be consulting with our workers because they’ve often got practical knowledge about controlling risks and what is available and suitable to do so, which we will find helpful.

So, consulting workers is not only a duty it’s actually a good way of doing business and doing business efficiently so moving on to section 152.

The Regulator

There are several sections about the regulator, but to my mind, they don’t add much. So, we’re just going to talk about Section 152, which is the functions of a regulator and the regulator has got several functions. So, they give advice and make recommendations to the relevant minister or Commonwealth Minister of the government. They monitor and enforce compliance with the act.

 They provide advice and information to duty holders and the community they collect analyse and publish statistics. They’re supposed to foster a co-operative, consultative relationship in the community to promote and support education and training and to engage in and promote and coordinate the sharing of information. And then finally they’ve got some legal duties with courts and industrial tribunals, and here’s the catch-all, any other function conferred on the regulator by the Act. If we look at the first six the ones that I’ve highlighted there are a number of regulators in Australia and because of the complexity of our federal government system, we’ve got.

 It’s not always clear which regulator you need to deal with and not all regulators are very good at this stuff. I have to say having worked in Europe and America and Australia, for example on Part D. Australian regulators are not very good at analyzing and publishing statistics in general. Usually, if you want high-quality statistics from a regulator, you’re usually better off looking at a European regulator in your industry or an American regulator. The Aussie ones don’t seem to be very good at that, in general.

There are exceptions. NOPSEMA, for example in the offshore world, are particularly good. But then you would expect because of the inherent dangers of offshore operations. Otherwise, I’ve not been that impressed with some of the regulators. The exception to that is Safe Work Australia. So, if you’re looking for advice and information, statistics, education and training and sharing of information then Safe Work Australia is your best bet. Now ironically Safe Work Australia is not a regulator.

Safe Work Australia

They are a statutory authority and they created, in consultation with many others I might say, they created a model WHS Act the model regulations and the Model Codes practice. So, if you go on their website you will find lots of good information on there and indeed I tend to look at that in order to find information to post on safety artisan. So, they’ve got some good WHS information on there. But of course, the wherever you go look at their site you must bear in mind that they are not the regulator of anything or anyone. So, for you’ve also got to go and look at the find the relevant regulator to your business or undertaking and you’ve got to look at what your regulator requires you to do.

 Very often when it comes to looking at guidance your best bet is safe work Australia okay.

Regulations and Codes of Practice

I’ve mentioned regulations and codes of practice. Basically, these sections of the act enable those codes of practice and regulations so the Minister has power to approve Commonwealth codes of practice and similarly state and territory ministers can do the same for their versions of WHS. This is very interesting and we’ll come back to relook at codes of practice in another session. An approved code of practice is admissible in court as evidence, it’s admissible as the test of whether or not a duty or obligation under the WHS Act has been complied with.

 And basically, the implication of this is that you are ignorant of codes of practice at your peril because if something goes wrong then codes of practice are what you will be judged against at minimum. So that’s a very important point to note and we’ll come back to that on another session.

Next, Codes of Practice and then regulation-making powers. For some unknown reason to me, the Governor-General may authorize regulations. I mean that doesn’t really matter. The codes of practice and the regulations are out there, and the regulations are quite extensive.  I think six hundred pages. So, there’s a lot of stuff in there. And again, we’ll do a separate session on WHS regulations soon OK.

That’s All Folks!

I appreciate we’ve covered quite a lot of ground there but of course, you can watch the video as many times as you like and go and look at the Act online. Mentioning that all the information I’ve shown you is pretty much word for word taken from the federal register of legislation and I’m allowed to do that under the terms of the license.

Creative Commons Licence

 And it’s one of those terms I have to tell you that I took this information yesterday on the 12th of October 2019. You should always go to that website to find the latest on Commonwealth legislation (and indeed if you’re working on it state or territory jurisdiction you should go and see the relevant regulator’s legislation on their site). Finally, you will find more information on copyright and attribution at the SafetyArtisan.com website, where I’ve reproduced all of the requirements, which you can check. At the Safety Artisan we’re very pleased to comply with all our obligations.

Now for more on this video, you may have seen it on Patreon on the Safety Artisan page or you may have seen it elsewhere, but it is for sure available Patreon.com/SafetyArtisan. Okay. So, thank you very much for listening and all that remains for me to do is to sign off and say thanks for listening and I look forward to presenting another session to you in a month’s time. Take care.

Back to the WHS Topic Page.

Categories
Mil-Std-882E Safety Analysis

Preliminary Hazard Analysis

In this 45-minute session, The Safety Artisan looks at Preliminary Hazard Analysis, or PHA, which is Task 202 in Mil-Std-882E. We explore Task 202’s aim, description, scope and contracting requirements. We also provide value-adding commentary and explain the issues with PHA – how to do it well and avoid the pitfalls.

This is the seven-minute-long demo video. The full video is 45 minutes’ long.

Topics: Preliminary Hazard Analysis

  • Task 202 Purpose;
  • Task Description;
  • Recording & Scope;
  • Risk Assessment (Tables I, II & III);
  • Risk Mitigation (order of preference);
  • Contracting; and
  • Commentary.

Transcript: Preliminary Hazard Analysis

Transcript: Preliminary Hazard Analysis

Hello and welcome to the Safety Artisan, where you’ll find professional, pragmatic and impartial safety training resources. So, we’ll get straight on to our session and it is the 8th February 2020. 

Preliminary Hazard Analysis

Now we’re going to talk today about Preliminary Hazard Analysis (PHA). This is Task 202 in Military Standard 882E, which is a system safety engineering standard. It’s very widely used mostly on military equipment, but it does turn up elsewhere.  This standard is of wide interest to people and Task 202 is the second of the analysis tasks. It’s one of the first things that you will do on a systems safety program and therefore one of the most informative. This session forms part of a series of lessons that I’m doing on Mil-Std-882E.

Topics for This Session

What are we going to cover in this session? Quite a lot! The purpose of the task, a task description, recording and scope. How we do risk assessments against Tables 1, 2 and 3. Basically, it is severity, likelihood and the overall risk matrix.  We will talk about all three, about risk mitigation and using the order of preference for risk mitigation, a little bit of contracting and then a short commentary from myself. In fact, I’m providing commentary all the way through. So, let’s crack on.

Task 202 Purpose

The purpose of Task 202, as it says, is to perform and document a preliminary hazard analysis, or PHA for short, to identify hazards, assess the initial risks and identify potential mitigation measures. We’re going to talk about all of that.

Task Description

First, the task description is quite long here. And as you can see, I’ve highlighted some stuff that I particularly want to talk about.

It says “the contractor” [does this or that], but it doesn’t really matter who is doing the analysis, and actually, the customer needs to do some to inform themselves, otherwise they won’t really understand what they’re doing.  Whoever does it needs to perform and document PHA. It’s about determining initial risk assessments. There’s going to be more work, more detailed work done later. But for now, we’re doing an initial risk assessment of identified hazards. And those hazards will be associated with the design or the functions that we’re proposing to introduce. That’s very important. We don’t need a design to do this. We can get in early when we have user requirements, functional requirements, that kind of thing.

Doing this work will help us make better requirements for the system. So, we need to evaluate those hazards for severity and probability. It says based on the best available data. And of course, early in a program, that’s another big issue. We’ll talk about that more later. It says including mishap data as well, if accessible: American term mishap, it means accident, but we’re avoiding any kind of suggestion about whether it is accidental or deliberate.  It might be stupidity, deliberate, whatever. It’s a mishap. It’s an undesirable event. We look for accessible data from similar systems, legacy systems and other lessons learned. I’ve talked about that a little bit in Task 201 lesson about that, and there’s more on that today under commentary. We need to look at provisions, alternatives, meaning design provisions and design alternatives in order to reduce risks and adding mitigation measures to eliminate hazards. If we can all reduce associated risk, we need to include all of that. What’s the task description? That’s a good overview of the task and what we need to talk about.

Reading & Scope

First, recording and scope, as always, with these tasks, we’ve got to document the results of the PHA in a hazard tracking system. Now, a word on terminology; we might call hazard tracking system; we might call it hazard log; we might call it a risk register. It doesn’t really matter what it’s called. The key point is it’s a tracking system. It’s a live document, as people say, it’s a spreadsheet or a database, something like that. It’s something relatively easy to update and change. And, we can track changes through the safety program once we do more analysis because things will change. We should expect to get some results and to refine them and change them as time goes on. Very important point.

Scope #1

Scope. Big section this. Let me just check. Yes, we’ve got three slides on scope. This does go on and on. The scope of the PHA is to consider the potential contribution from a lot of different areas. We might be considering a whole system or a subsystem, depending on how complex the thing is we’re dealing with. And we’re going to consider mishaps, the accidents and incidents, near misses, whatever might occur from components of the system (a. System components), energy sources (b. Energy sources), ordnance (c. Ordnance)- well that’s bullets and explosives to you and me, rockets and that kind of stuff.

Hazardous materials (d. Hazardous Materials (HAZMAT)), interfaces and controls (3. Interfaces and controls), interface considerations to other systems (f. Interface considerations to other systems when in a network or System-of-Systems (SoS) architecture), external systems. Maybe you’ve got a network of different systems talking to each other. Sometimes that’s called a system of systems architecture. Don’t worry about the definitions. Our system probably interacts and talks to other systems, or It relies on other systems in some way, or other systems rely on it. There are external interfaces. That’s the point.

Scope #2

We might think about material compatibilities (g. Material Compatibilities) – Different materials and chemicals are not compatible with others-, inadvertent activation (h. Inadvertent activation).

Now, I’ve highlighted I. (Commercial-Off-the-Shelf (COTS), Government-Off-the-Shelf (GOTS), Non-Developmental Items (NDIs), and Government-Furnished Equipment (GFE).) because it’s something that often gets neglected. We also need to think about stuff that’s already been developed. The general term is NDIs and it might be commercial off the shelf, it might be a government off the shelf system, or government-furnished equipment  GFE- doesn’t really matter what it is. These days, especially, very few complex systems are developed purely from scratch. We try and reuse stuff wherever we can in order to keep costs down and schedule down.

We’re going to need to integrate all these things and consider how they contribute to the overall risk picture. And as I say, that’s not often done well. Well, it’s hardly ever done well. It’s often not done at all. But it needs to be, even if only crudely. That’s better than nothing.

J. (j. Software, including software developed by other contractors or sources.  Design criteria to control safety-significant software commands and responses (e.g., inadvertent command, failure to command, untimely command or responses, and inappropriate magnitude) shall be identified, and appropriate action shall be taken to incorporate these into the software (and related hardware) specifications)  we need to include software, including software developed elsewhere. Again, that’s very difficult, often not done well. Software is intangible. If somebody else has developed it maybe we don’t have the rights to see the design, or code, or anything like that. Effectively it’s a black box to us. We need to look at software. I’m not going to bother going through all the blurb there.

Another big thing in part k (k.  Operating environment and constraints) is we need to look at the operating environment. Because a piece of kit that behaves in a certain way in one environment, you put it in a different environment and it behaves differently. And it might become much more dangerous. You never know. And the constraints that we put under on system. Operating environment is very big. And in fact, if you see the lesson I did on the definition of safety, we can’t really define whether a system is safe or not until we define the operating environment. It’s that important, a big point there.

Scope #3

And then third slide of three procedures (l. Procedures for operating, test, maintenance, built-in-test, diagnostics, emergencies, explosive ordnance render-safe and emergency disposal). Again, these are well these often don’t appear until later unless of course, we’ve gone off the shelf system. But if we have got off the shelf system; there should be a user manual, there should be maintenance manuals, there should be warnings and cautions, all this kind of stuff. So, we should be looking for procedures for all these things to see what we could learn from them. We want to think about the different modes (m. Modes) of operation of the system. We want to think about health hazards (n. Health hazards) to people, environmental impacts (o. Environmental Impacts), because they take to includes environmental.

We need to think about human factors, human engineering and human error analysis (p. Human factors engineering and human error analysis of operator functions, tasks, and requirements). And it says operator function tasks and requirements, but there’s also maintenance and disposal of storage. All the good stuff. Again, Human Factors is another big issue. Again, it’s not often done well, but actually, if you get a human factor specialist statement early, you can do a lot of good work and save yourself a lot of money, and time, and aggravation by thinking about things early on.

We need to think about life support requirements (q.  Life support requirements and safety implications in manned systems, including crash safety, egress, rescue, survival, and salvage). If the system is crewed or staffed in some way, I’m thinking about, well, ‘What happens if it crashes?’ ‘How do we get out?’ ‘How do we rescue people?’ ‘How do we survive?’ ‘How do we salvage the system?’

 Event-unique hazards (r. Event-unique hazards). Well, that’s kind of a capsule for your system does something unusual. If it does something unusual you need to think about it.

And then thinking about part s. infrastructure (s.  Built infrastructure, real property installed equipment, and support equipment), property installed equipment and support equipment in property and infrastructure.

And then malfunctions (t. Malfunctions of the SoS, system, subsystems, components, or software) of all the above.

I’m just going to whizz back and forth. We’ve got to sub-item T there. We’ve got an awful lot of stuff there to consider. Now, of course, this is kind of a hazard checklist, isn’t it? It’s sort of a checklist of things. We need to look at all that stuff. And in that respect, that’s excellent, and we should aim to do something on all of them just to see if they’re relevant or not if nothing else. The mistake people often make is because they can’t do something perfect and comprehensive, they don’t do anything. We’ve got a lot of things to go through here. And it’s much better to have a go at all these things early and do a bit of rough work in order to learn some stuff about our system. It’s much better to do that than to do nothing at all. And with all of these things, it may be difficult to do some of these things, the software, the COTS, things where we don’t have access to all the information, but it’s better to do a little bit of work early than to do nothing at all waiting for the day to arrive when we’ll be able to do it perfectly with only information. Because guess what? That day never comes! Get in and have a go at everything early, even if it’s only to say, ‘I know nothing about this subject, and we need to investigate it.’ That’s the pros and cons of this approach. Ideally, we need to do all these things, but it can be difficult.

Risk Assessment

Moving on. Well, we’ve looked to a broad scope of things for all the hazards that we identify and there are various techniques you can use. The PHA has go to include a risk assessment. That means that we’ve got to think about likelihood and severity and then that gives us an overall picture of risk when we combine the two together. That’s tables 1 and 2.

And then, forget risk assessment codes I’m not sure why that’s in there, table 3 is the risk matrix and 88 2 has a standard risk matrix. And it says use that unless you’ve got a tailored matrix for your system that’s been approved for use. And in this case, it says approved effectively in accordance with the US Department of Defence. But it’s whoever is the acquiring organization, the authority, the customer, the purchaser, whatever you want to call it, the end-user. We’ll talk about that more in a sec.

Table I, Severity

Let’s start by looking at severity, which in many ways is the easiest thing to look at. Now, here we’ve got in this standard we’ve got an approach based on harm to people, harm to the environment, and monetary loss due to smashing stuff up. At the top catastrophic accident. Category 1 is a fatal accident. This accident could result in death, permanent total disability, irreversible significant environmental impact, or monetary loss. And in this case, it says $10 million. Well, this, that’s 10 million US dollars. This standard was created in 2012, this version of the standard, probably inflation has had an effect since then. And a critical accident, we could cause partial disability injuries or occupational illness that can hospitalized three people are reversible. Significant environmental impact or some losses between 1 million and 10. And then we go down to marginal. Injury or hospital, lost workdays for one person, reversible moderate environmental impact or monetary loss between $100,000 and one million dollars. And then finally negligible is less than that. Negligible is an injury or illness that doesn’t result in any lost time at work, minimal environmental impact, or a monetary loss of less than a hundred thousand dollars. That’s easy to do in this standard. We just say, ‘What are our losses that we think could result?’ Worst case, reasonable scenario or an accident? That’s straightforward.

Table II, Probability

Now let’s look at probability. We’ve got a range here from ‘a’ to ‘e’, frequent down to improbable, and then F is eliminated. And eliminated in the standard really does mean eliminated. It cannot happen ever! It does not mean that we managed to massage the figures, the likelihood a probability figures, down Low that we pretend that it will never happen. It means that it is a physical impossibility. Please take note because I’ve seen a lot of abuse of that approach. That’s bad practices to massage the figures down to a level where you say, ’I don’t need to bother thinking about this at all!’ because the temptation is just to frig [massage] the figures and not really consider stuff that needs to be considered. Well, I’ll get off my soapbox now.

Let’s go back to the top. Frequent- you’ve said, for one item, likely to occur often. Down to probable- occur several times in the life of an item. Occasional- likely to occur sometimes, we think it’ll happen once in the life of an item. Remote- we don’t think it’ll happen at all, but it could do. And improbable – so unlikely for an individual item that we might assume that the occurrence won’t happen at all. But when we consider a fleet, particularly, I’ve got hundreds or thousands of items, the cumulative risk or cumulative probability, sorry, I should say, is unlikely to occur across the fleet, but it could.

And this is where this specific vs. fleet occurrence or probability is useful. For example, if we think ‘Let’s imagine a frequent hazard’. We think that something could happen to an item, per item, let’s say once a year. Now, if we’ve got a fleet of fifty of these items or fifty-something of these items, that means it’s going to happen across the fleet pretty much every week on average. That’s the difference. And sometimes it’s helpful to think about an individual system. And sometimes it’s helpful to think about a fleet where you can you’ve got relevant experience to say, ‘Well the fleet that we’re replacing. We had a fleet of 100 of these things. And we at this go, this went wrong every week or every month or once a year or only happened once every 10 years across the entire fleet.’ And therefore, we could reason about it that way.

We’ve got two different ways of looking at probability here. And use whichever one is more useful or helps you. But when we’re doing that, try and do that with historical data, not just subjective judgment. Because otherwise your subjective judgment, one individual might say ‘That will never happen!’, whereas another will say, ‘Well, actually we experienced it every month on our fleet!’. Circumstances are different.

Table III, Risk Matrix

We put severity and probability together. We have got 1 to 4 on severity, A to F on probability, and we get this matrix. We’ve got probability down the side and severity along the top. And in this standard, we’ve got high risk, serious risk, medium risk and low risk. And now how exactly you define these things is, of course, somewhat arbitrary. We’ll just look at some general principles.

The good thing about this risk matrix is- First, the thing to remember is that risk is the product of probability and severity. Effectively we multiply the two together and we go, well, if we’ve got a catastrophic or a critical risk. And it’s if we’ve got a more serious risk and it’s going to happen often that’s a big risk. That’s a that’s a high risk. Where alternatively, if we’ve got a low severity accident that we think will happen very, very rarely, then that’s a low risk. That’s great.

One thing to note here it’s easier to estimate the severity than it is the probability. It’s quite easy to under- or overestimate probability. Usually, because of the physical mechanism involved, it’s easier to estimate the severity correctly. If we look on the right-hand side, at negligible. We can see that if we’re confident that something is negligible, then it can be a low risk. But at the very most, it can only be a medium risk. We are effectively prioritizing negligible severity risks quite low down the pecking order.

Now, on the other side, if we think we’ve got a risk that could be catastrophic, we could kill somebody or do irreversible environmental damage, then, however improbable we think it is, it’s never going to be classified less than medium. That’s a good point to note. This matrix has been designed well, in the sense that all catastrophic and critical risks are never going to get the low medium and they can quite easily become serious or high. That means they’re going to get serious management attention. When you put risks up in front of a manager, senior person, a decision-maker, who’s responsible and they see red and orange, they’re going to get uncomfortable and they’re going to want to know all about that stuff. And they will want to be confident that we’ve understood the risk correctly and it’s as low as we can get it. This matrix is designed to get attention and to focus attention where it is needed.

And in this standard, in 88, you ultimately determine whether you can accept risk based on this risk rating. In 882, there is no unacceptable, intolerable risk. You can accept anything if you can persuade the right person with the right amount of authority to sign it off. And the higher the risk, the higher the level of authority you must get in order to accept the risk and expose people to it. This matrix is very important because it prioritizes attention. It prioritizes how much time and effort money gets spent on reducing risks. You will use it to rank things all the time and it also prioritizes, as we’ll see later, how often you review a risk because clearly, you don’t want to have high risks or serious risks. Those are going to get reviewed more often than a medium risk or low risk. A low risk might just get review routinely, not very often, maybe once a year or even less. We want to concentrate effort and attention on high risks and this matrix helps us to do that. But of course, no matrix is perfect.

Now, if we go back. Looking at the yellow highlight, we’re going to use table three unless there’s a tailored alternative definition, a tailored alternative matrix. Now, noting this matrix, catastrophic risk, the highest possible risk, we’ve got one death. Now, if we had a system where it was feasible to kill more than one person in an accident, then really, we would need another column worse than catastrophic. We could imagine that if you had a vehicle that had one person in it and the vehicle crashed, whatever it was, a motorbike let’s say. Let’s imagine you only said ‘We’re only going to have solo riders. We can only kill one person.’. We’re assuming we won’t hurt anybody else. But if you’ve got a car where you’ve got four or more people in, you could kill several people. If you’ve got a coach or a bus, you could drive it off a cliff and kill everybody, or you might have a fire and some people die, but most of them get out. You can see that for some vehicles, for some systems, you would need additional columns. Killing one person isn’t the worst conceivable accident.

Some systems. You might imagine quite easily, say with a ship, it’s actually very rare for a ship to sink and everybody dies. But it’s quite common for individuals on ships to die in health and safety type accidents, workplace accidents. In fact, being a merchant seaman is quite a risky occupation. But also in between those two, it’s also quite possible to have a fire or asphyxiating gases in a compartment. You can kill more than one person, but you won’t kill the entire ship’s company. Straight away in a ship, you can see there are three classes, if you like, of serious accidents where you can kill people. And we knew we should really differentiate between the three when we’re thinking about risk management. And this matrix doesn’t allow you to do that. If you’ve got a system where more than one death this is feasible, then this matrix isn’t necessarily going to serve well, because all of those type of accidents get shoved over into a catastrophic column, on this matrix, and you don’t differentiate between any of between them which is not helpful. You may need to tailor your matrix and add further columns.

And depending on the system, you might want to change the way that those risks are distributed. Because you might have a system, for example riding a bicycle. It’s very common riding a bicycle to get negligible type injuries. You know you fall off, cuts and bruises, that kind of thing. But, if you’re not on the road, let’s say you’re riding off-road it is quite rare to get utilities unless you do a mountain biking on some extreme environment. You’ve got to tailor the matrix for what you’re doing. I think we’ve talked about that enough. We’ll come back to that in later lessons, I’m sure.

Risk Mitigation

Risk mitigation, we’re doing this analysis, not for the sake of it, we’re doing it because we want to do something about it. We want to reduce the risk or eliminate it if we can. 88 2 standard gives us an order of precedence, and as it says it’s specified in section 4.3.4, but I’ve reproduced that here for convenience. Ideally, we would like to eliminate hazards by designing them. We would make a design decision to say, ‘We will- we won’t have a petrol engine, let’s say, in this vehicle or vessel because petrol a serious fire explosion hazard. We’ll have something else. We’ll have diesel or we’ll have an all-electric vehicle maybe these days or something like that.’ We can eliminate the risk.

We could reduce the risk by altering the design introducing sort of failsafe features, or making the design crashworthy, or whatever it might be. We could add engineered features or devices to reduce risk safety features seatbelts in cars or airbags, roll balls, crash survivable cages around the people, whatever it might be. We can provide warning devices to say ‘Something’s going wrong here, and you need to pull over’ or whatever it is you need to do. ‘Watch out!’ because the system is failing and maybe ‘Your brakes are failing. You’ve got low brake fluid. Time to pull over now before it gets worse!’.

And then finally, the least effective precautions or mitigations signage, warning signs – because nobody reads warning signs, sadly. Procedures. Good, if they’re followed. Again, very often people don’t follow them. They cut corners. We train people. Again, they don’t always listen to the training or carry it out. And we provide PPE. That’s personal protective equipment. And again, PPE is great if you enforce it. For example, I live in Australia. If you cycle in Australia, if you ride a bicycle, it’s the law that you wear a bike helmet. Most people obey the law because they don’t want to get a $300 fine or whatever it is if the cops catch you, but you still see people around who don’t wear one. Presumably, because they think they’re bulletproof, and it will never happen to them. PPE is fine if it’s useful. But of course, sometimes PPE can make a job that much harder that people discard it. We really need to think about designing a job to make it easy to do, if we’re going to ask people to wear awkward PPE. Also, by the way, we need to not ask them to wear PPE for trivial reasons just so that the managers can cover their backsides. If you ask people to wear PPE when they’re doing trivial jobs where they don’t need it then it brings the system into disrepute. And then people end up not wearing PPE for jobs where they really should be wearing it. You can over-specify safety and lose goodwill amongst your workers if you’re not careful.

Now those risk mitigation priorities, that’s the one in this standard, but you will see an order of precedence like that in many different countries in the law. It’s the law in Australia. It’s the law in the UK, for example, expressed slightly differently. It’s in lots of different standards for good reason because we want to design out the risks. We want to reduce them in the design because that’s more effective than trying to bolt on or stick home safety afterwards. And that’s another reason why we want to get in early in a project and think about our hazards and our risks early on. Because it’s cheaper at an early stage to say, ‘We will insist on certain things in the design. We will change the requirements to favour a design that is inherently safe.’

Contracting

We only get these things if we contract for them. The model in 88 2, the assumption is it’s a government somewhere contracting a contractor to do stuff. But it doesn’t have to be a government, it can be any client or purchase of world authority or end-user asking for something, buying something, contracting something, be it the physical system, or service, or whatever it might be. The assumption is that the client issues a request for proposal.

Right at the start, they say ‘I want a gizmo’. Or ‘I want- I don’t even want to specify that I want a gizmo. I want something that will do this job. I don’t care what it is. Give me something that will do this job.’ But even at that early stage, we should be asking for preliminary hazard analysis (PHA) to be done. We should be saying, ‘Well, who?’ ‘Which specialists?’ ‘Which functional disciplines need to be involved?’. We need to specify the data that we require and the format that it’s in. Considering, especially the tracking system, which is task 106. If we’re going to get data from lots of different people, best we get it in a standardized format we can put it all together. We want to insist that they identify hazards, hazardous locations, etc. We want to insist on getting technical data on non-developmental items, either getting it for the client or the client supplies it. Says to the contractor or doing it ‘This is the information that I’m going to supply you’ and you will use it. We need to supply the concept of operations and of course, the operating environment. Let me just check, no that that’s it. We’ve only got one slide on commentary. It doesn’t say the environment, but we do need to specify that as well, and hopefully that should be in the concept of operations, and a specific hazard management requirement. For example, what matrix are we going to use? What is a suitable matrix to use for this system?

Now to do all of this, the purchaser, the client really probably needs to have done Task 202 and 201 themselves, and they’ve done some thinking about all of this in order to say, ‘With this system, we can envisage- with this kind of requirement, we can envisage these risks might be applicable.’ And ‘We think that the risks might be large or small’ depending on what the system is or ‘We think that-’. Let’s say if you if you purchase a jet fighter, jet fighters because of that demand, the overwhelming demand for performance, they tend to be a bit riskier than airliners. They fall out of the sky more often. But the advantages, there’s normally only one or two people on board. And jet fighters tend to fly a lot of the time in the middle of nowhere. You’re likely to hurt relatively few people, but it happens more often.

Whereas if you’re buying an airliner something, you can shove a couple of hundred people in at one go, those fall out of the sky much less frequently, thank goodness, but when they do, lots of people get hurt. Aa different approach to risk might be appropriate for different types of system. And when your, you should be thinking about early on, if you’re the client, if you’re the purchaser. You should have done some analysis to enable you to write a good request for proposal, because if you write a bad request for proposal, it’s very difficult to recover the situation afterwards because you start at a disadvantage. And the only way often to fix it is to reissue the RFP and start again. And of course, nobody wants to do that because it’s expensive and it wastes a lot of time. And it’s very embarrassing. It is a career-limiting thing to do, a lot of people. You do need to do some work up front in order to get your RFP correct. That’s what it says in the standard.

Commentary

I want to add a couple of comments, I’m not going to say the much. First, it’s a little line from a poem by Kipling that I find very, very helpful. And Kipling used to be a journalist and it was it was his job to go out and find out what the story was and report it. And to do that he used his six honest serving men. He asked ‘What?’ and ‘Why?’ and “When?’ and ‘Who?’, sorry, and ‘How?’ and ‘Where?’ and ‘Who?’. Those are all good questions to ask. If you can ask all those questions and get definite answers, you’re doing well. And a little tip here as a consultant, I rock up and one of the tricks of the trade I use is I turn up as the ‘dumb consultant’ – I always pretend to be a bit dumber than what I really are- and I ask these stupid questions. And I ask the same questions of several different people. And if I get the same answer to the same question from everyone, I’m happy. But that doesn’t always happen. If you start getting very different answers to the same question from different people, then you think, ‘Okay, I need to do some more digging here’. And it’s the same with hazard analysis. Ask the what, why, when, where and who question.

Another issue, of course, is ‘How much?’ ‘How much is this going to take?’ ‘How long is this going to take?’ ‘How many people am I going to have to invite to this meeting?’, etc. And that’s difficult. And really, the only way to answer these questions properly is to just do some PHI and PHA early and to learn from the results. The other alternative, which we are really good as human beings, is to ask the questions early to get answers that we don’t really like and then just to sweep them under the carpet and not ask those questions ever again because we’re frightened of the answers that we might. However frightened you are of the answer, you might get do ask the question because forewarned is forearmed. And if you know about a problem, you can do something about it. Even if that something is to rewrite your CV and start looking for another job. Do ask the questions even if it makes people uncomfortable. And I guess learning how to ask the questions without making people uncomfortable is one of the tricks that we must learn as safety engineers and consultants. And that’s an important part of the job. The soft skills really that you can only learn through practice, really, and observing people.

What’s the way to do it? Well, I’ve said this several times but do your PHI and PHA early. Do it as early as possible because it’s cheap to do it early. If you’re the only safety person or safety, you often in the beginning, maybe you’re a manager, maybe safety is part of your portfolio, you’ve got other responsibilities as well. Just sit down one day and ask these dumb questions, go through the checklist in Task 202 and say, ‘Do I have these things in my system?’

If you know for sure you’re not going to have explosive ordnance, or radiation, or whatever it might be, you can go, ‘Great. I can cross those off the list’. I can make an assumption or I can put a constraint in, by the way, if you really want to do it well and say ‘We will have no explosive devices’, ‘We will have no energetic materials.’, ‘We will have no radiation’ or whatever it might be. Make sure that you insist that you’ll have none of it then you can hopefully move on and never have to deal with those issues again.

Do the analysis early, but expect to repeat it because things change, and you learn more and more information comes in. But of course, the further you go down the project, the more expensive everything gets. Now, having said do it, do it early, the Catch 22 is very often people think ‘How can I analyse when I don’t have a design?’

The catch 22 question is what comes first, design or analysis? Now, the truth is that you could do analysis on very simple functions. You don’t need any design at all. You don’t even need to know what kind of vehicle or what kind of system you might dealing with. But of course, that will only take you so far. And it may be that you want to do early analysis, but for whatever reason, [Intellectual Property Rights] IPR or whatever it might be, you can’t get access to data.

What do you do? You can’t get access to data about your system or the system that you’re replacing. What do you do? Well, one of the things you can do is you can borrow an idea from the logistics people. Logistic support analysis Task 203 is a baseline comparison system. Imagine that you’re going to have a new system, maybe is replacing an old system, but maybe it does a lot more than the old system used to do. Just looking at the old system isn’t going to give you the full picture. Maybe what you need to do is make up an imaginary comparison system. You take the old system and say, ‘Well, I’m adding all this extra functionality’. Maybe the old system, we just bought the vehicle. We didn’t buy the support system, we didn’t buy the weapons, we didn’t buy the training, whatever it might be. But, this time round, we’re buying the complete package. We’re going to have all this extra stuff that probably has hazards associated with it, but just doing lessons learned from the previous system will not be enough.

Maybe you need to construct an imaginary Baseline Comparison System and go, ‘I’ll borrow bits from all these other systems, put them all together, and then try and learn from that sort of composite system that I’ve invented, even though it’s imaginary.’ That can be a very powerful technique. You may get told, ‘Oh, we haven’t got the money’ or ‘We haven’t got the time to do that’. But to be honest, if there’s no other way of doing effective, early analysis, then spend the money and do it early. Because many times I’ve seen people go, ‘Oh, we haven’t got time to do that’. They’ve never got time to do it properly and therefore, you end up doing it. You go around the buoy two or three times. You do it badly. You do it again slightly less badly. You do it a third time. And it’s sort of barely adequate. And then you move forward. Well, you’ve wasted an awful lot of time and money and held up other people, the rest of the project doing that. Probably it’s better off to spend the money and just get on with it. And then you’re informed going forwards before you start to spend serious money elsewhere on the project.

Copyright Statement

Well, that’s it for me. Just one thing to say, that Mil. Standard 882E came out in 2012. Still going strong, unlikely to be replaced anytime soon. It’s copyright free. All the quotations are from the standard, they’re copyright free. But this video is copyright of The Safety Artisan 2020.

For More …

And you can find a lot more information, a lot more safety videos, at The Safety Artisan page at www.Patreon.com and you can find more resources at www.safetyartisan.com.

End

That is the end of the show. Thank you very much for listening. And it just remains for me to say. Come and watch some more videos on Mill-Std-882E. There’s going to be a complete course on them, and you should be able to get, I hope, a lot of value out of the course. So, until I see you again, cheers.

End: Preliminary Hazard Analysis

You can find a free pdf of the System Safety Engineering Standard, Mil-Std-882E, here.

Categories
Mil-Std-882E Safety Analysis

System Requirements Hazard Analysis

In this 45-minute session, The Safety Artisan looks at System Requirements Hazard Analysis, or SRHA, which is Task 203 in the Mil-Std-882E standard. We explore Task 203’s aim, description, scope, and contracting requirements.  SRHA is an important and complex task, which needs to be done on several levels to be successful.  This video explains the issues and discusses how to perform SRHA well.

This is the seven-minute demo video, the full version is 40-minutes’ long.

Topics: System Requirements Hazard Analysis

  • Task 202 Purpose;
  • Task Description:
    • Determine Requirements;
    • Incorporate Requirements; and
    • Assess the compliance of the System.
  • Contracting;
  • Section 4.2 (of the standard); and
  • Commentary.
Transcript: System Requirements Hazard Analysis

Introduction

Hello and welcome to the Safety Artisan, where you will find professional, pragmatic and impartial advice on all things system, safety and related.

System Requirements Hazard Analysis

And so today, which is the 1st of March 2020, we’re going to be talking about – let me just find it for you – we’ll be talking about system requirements, hazard analysis. And this is part of our series on Mil. Standard 882E (882 Echo) and this one a task 203. Task 203 in the Mil. standard. And it’s a very widely used system safety engineering standard and its influence is found in many places, not just on military procurement programs.

Topics for this Session

We’re going to look at this task, which is very important, possibly the most important task of all, as we’ll see. so in to talk about the purpose of the task, which is word for word from the task description itself. We’re going to talk about in the task description, the three aims of this task, which is to determine or work out requirements, incorporate them, and then assess the compliance of the system with those requirements, because, of course, it may not be a simple read-across. We’ve got six slides on that. That’s most of the task. Then we’ve just got one slide on contracting, which if you’ve seen any of the others in this series, will seem very familiar. We’ve got a little bit of a chat about Section 4.2 from the standard and some commentary, and the reason for that will become clear. So, let’s crack on.

System Requirements Hazard Analysis

Task 203.1, the purpose of Task 203 is to perform and document a System Requirements Hazard Analysis or SRHA. And as we’ve already said, the purpose of this is to determine the design requirements. We’re going to focus on design rather than buying stuff off the shelf – we’ll talk about the implications of that a little bit later. Design requirements to eliminate or reduce hazards and risks, incorporate those requirements, into a says, into the documentation, but what it should say is incorporate risk reduction measures into the system itself and then document it. And then finally, to assess compliance of the system with these requirements. Then it says the SRHA address addresses all life-cycle phases, so not just meant for you to think about certain phases of the program. What are the requirements through life for the system? And in all modes. Whether it’s in operation, whether it’s in maintenance or refit, whether it’s being repaired or disposed of, whatever it might be.

Task Description #1

First of six slides on the task description. I’m using more than one colour because there’s some quite a lot of important points packed quite tightly together in this description. We’re assuming that the contractor performs and documents this SRHA. The customer needs to do a lot of work here before ever gets near a contractor. More on that later. We need to determine system design requirements to eliminate hazards or reduce associated risks.

Two things here. By identifying applicable policies, regulations and standards etc. More on that later. And analysing identified hazards. So, requirements to perform the analysis as well as to simply just state ‘We want a system to do this and not to do that’. So, we need to put some requirements to say ‘Here’s what we want analysed maybe to what degree? And why.’ is always helpful.

Task Description #2

Breaking those breaking those two requirements down.

Part a. We’re going to identify applicable requirements by reviewing our military and industry standards and specs, historical documentation of systems that are similar or with a system that we’re replacing, perhaps. Look at, it’s assumed that the US Department of Defense is the customer, ultimate customer. So, the ultimate customer’s requirements, including whatever they’ve said about standard ways of mitigating certain common risks. System performance spec, that’s your functional performance spec or whatever you want to call it. Other system design requirements and documents- Bit of a catchall there. And applicable federal, military, state and local regulations. This is a US standard. It’s a federated system, much like Australia or indeed lots of modern states, even the UK. There are variations in law across England, Wales, Scotland and Ireland. They’re not great, but they do exist. And in the US and Australia, those differences are greater. And it says applicable executive orders. Executive orders, they’re not law, but they are what the executive arm of the U.S. government has issued, and international agreements. A lot of words in there- have a look at the different statements that are in that in white, blue and yellow. Basically, from international agreements right down to whatever requirements may be applicable, they all need to be looked at and taken account of. So, there’s a huge amount of work there for someone to do. I’ll come back to who that someone should be later.

Task Description #3

Part B. It says the contractor shall recommend appropriate system design requirements. The assumption here is that the contractor is the designer and knows the design better than anybody, better than the purchaser, which is fair enough. It’s your system, you should understand it. And the requirement is that the contractor is not just passive, ‘doing as they’re told’, they’re there to actively investigate possible hazards associated with their system and recommend appropriate requirements in order to manage those hazards and risks. And then there’s further guidance here is the contractor to do that in accordance with Section 4 of Mil. Standard 882E. Now, Section 4 is the general requirements of the standards and there’s lots of good advice in that. And I’ll be doing a lesson, maybe more than one lesson in fact, on Section 4 because there is quite a lot in there. The contractor is to refer to the standard and apply the principles therein. All good stuff.

Part C. The contractor shall also define verification and validation approaches. So, the contractor shall define V and V approaches for each design requirement to eliminate hazards and reduce risks. In part C- Well, B and C- we’ve got a very much narrower focus on requirements to eliminate hazards or reduce risks. Whereas in A, notice we’ve got incredibly broad scope looking requirements. It’s not just about the narrow job of dealing with hazards and controlling them, that we’ve got in parts B and C.

Task Description #4

Onwards and upwards. We get to the second major part of this task, which is to incorporate those design requirements. It’s all very well to have them, but they’ve got to be built into the engineering design, into documentation, hardware, software, test plans, etc. And the second highlighted bit that I’ve got is ‘as the design evolves ensure applicable design requirements flow down into lower-level specifications’, etc, etc, etc. There’s a lot of repetition there, so I won’t go through it. Clearly the assumption in this standard is that the design will be done top-down and that the main contractor, design contractor, will be doing work and then identifying lower-level requirements to be passed on to subcontractors and suppliers. And again, the assumption is we’re dealing with a large military system, which is at least, in part, bespoke. It is being developed and/or integrated for the first time for a specific user and a specific use.

I’ll come onto the third yellow highlighted bit first, and then it says as appropriate use engineering change proposals to incorporate applicable design requirements into these documents. What we’re saying here is that even if something hasn’t been specified up front in the original contract, the contractor should use Engineering Change Proposals – ECP – should use it controlled change mechanism in order to change things as they go with approval and refine and evolve the design.

Years of experience have taught me that these statements are coming from the assumption – still true in the US, I believe – whereby major military projects are designed and developed under a cost-plus basis. In other words, the government pays the main contractor / the prime contractor / prime designer on a sort of time and materials basis, not on a firm or fixed price basis, but says ‘Go away and do what we say’. And there’s controls there, and there’s open-book accounting to try and prevent the government being defrauded. But basically, the contractor goes off and does what is required and gets paid for what they do. So, the government has transferred relatively low amounts of risk onto the contractor anticipating that this will result in the lowest possible overall cost of design development. Now, as we probably could know from the news, that doesn’t always work. However, that is the assumption behind this standard. This cost-plus approach will pay you to do the job and therefore we don’t have to specify every single nut and bolt in the contract right at the beginning. Which in some ways takes a lot of risk away from the purchaser because they don’t have to get everything right at the start. So that’s good. There’s always a balance of risk in whichever approach we take.

So, if we go firm price, yes, we could inject more competition into procurement and supply activity, but you’ve got to get your contract upfront right. And all your requirements, right- more or less. That is notoriously difficult to do. Whichever way you go, there are risks. But it’s important to note that this is the assumption underlying the standard. Not every standard follows this approach, follows this philosophy, but 88 2 does. So, if we’re going to use it in a different way, we need to understand the fact that in. More on that later.

Task Description #5

Fifth slide of six. Third part. We need to assess compliance of that development of hardware, software, documentation, data, etc., whatever it might be. In order to do that, the contractor is going to have to address the customer requirements at technical reviews. So again, the assumption is that development is following a systems-engineering process with certain gated reviews. So, you go into a series of reviews, you might start with system requirements review, SRR. Then you might have preliminary design review, top-level design, PDR. And then we go down to detailed design which is reviewed at Critical Design Review, or CDR. And then we might have a further software specification review for software components and then we’ll go on and test readiness routines and so on and so forth. Mil. Standard 882 is assuming a particular systems-engineering-lifecycle approach to development. This is very widely used not just for military standards, but for civil, and all over the place. Whatever we call these reviews, the idea of a gated review is that you don’t start a review until you’ve reached maturity requirements or design. You then conduct the review against objective criteria and then decide whether the review has passed. Now, usually, there is a hefty payment milestone associated with passing review. The contractor is incentivized to pass the review. And hopefully, if we’ve got the requirements right, a passed review means we’re on the right track and we’re getting the right product. But that’s not always that’s not always the case that we’ve got to get all these things right.

And then it says during those reviews, the contractor shall address hazards, mitigation measures or controls and methods of V and V, and recommendations arising. A lot goes on at these reviews. They are on big programs, especially, the very important, very high stress. And in fact, in Australia now, there are some projects that are so big that a delay in a PDR review actually made it into the national news on the future submarine because it’s such a huge multibillion-dollar project. It could all get very painful and political as well.

Task Description #6

However, let’s move on to the final slide of the task description. So, A. was is do the reviews. B. is review test plans and review test results to make sure to verify and validate hardware and software compliance with those requirements. And as it says, this includes V and V of the effectiveness of risk mitigation measures. So, we need to test these risk controls where we can and see how effective they are and whether they live up to the requirements or the assumptions that we’ve made. Now, again, this is an American standard, so it’s very test centric. American government likes to test things to death and depending on your point of view, that’s sensible or not, it’s sensible in the sense that you’re testing a real system hopefully in a representative test environment. Although it’s going to be representative of the operational environment. So, it should be a very solid, robust, valid approach to proving a system.

However, there is a downside to testing in that it’s very expensive and it tends to come at the end of a program. Whereas really you need an indication much earlier on if things are going astray. So, you really need to review documentation and do analysis and so forth. Or maybe you maybe you test a prototype for some samples or something early on, rather than waiting until yet when it’s often may be too late and then very expensive to fix things.

And then part C, we need to ensure that hazard control information is incorporated into manuals and plans, whether it be for the operator, the maintainer, the trainer, the logistician, the diagnostics or indeed for the final disposal. We need to take that hazard control information, risk control information, and record it so that it doesn’t get lost and it gets to the people who need it. That’s very important.

OK, so we’ve spent quite a lot of time going through the description because it’s a big, complex task this one, as you can see, with three major parts to it. It’s worth just going back over it. We’ve got our top-level description on slide one, which summarizes the whole thing. We’re talking about finding those requirements, identifying them. We’re talking about the contractor as an active recommender and developer of requirements and actively developing the V and V techniques to make sure that they’re met. Second major part, we’re talking about incorporating those design requirements as the design evolves and using a controlled change method to make sure that we keep up with what’s going on. We’re talking about assessing compliance both at major systems engineering reviews and during testing. And then finally, we’re talking about making sure that the required information gets through to those who need it at the end of the food chain, as it were. All important stuff.

Contracting

Here’s as a page we should be familiar with by now, contracting. We need to require SRHA, Task 203.  We need to put it in the request for proposal and the contractual state, the work. So once again, as I’ve said before, we’ve got to get this stuff in early on. At least the requirement to do it, even if we haven’t fully worked everything out. We need to get that in right at the start of the request for proposal. We need to require task 203 to be done. It’s imposed (A. Imposition of Task 203).

We need to identify (B. Identification of functional disciplines) who we want to take part in it because it’s not, as we will see, it’s not just the discipline and the job of the safety engineers or the safety team to do this. The design engineers, the specialist engineers in reliability, maintainability and testability, whoever, they all need to be involved as well, etc, etc.

Contractor level of effort (C.) for reviews and so on. We may need to specify some hard requirements there to ensure that we get early scrutiny of the product and the design.

Big point tailoring of the task (D. Tailor 203.2 and 203.2.3 as appropriate). The task may need to be tailored assuming again that the contractor is responsible for the design. Maybe if the prime contractor isn’t responsible for the design, maybe we’re contracting somebody to buy something that’s mostly off the shelf and then operating force for 30 years. Let’s say a so-called turnkey solution. And we might do that for a piece of military kit, or we might do that for a hospital, or whatever it might be. A piece of infrastructure, a service, whatever. So, it may be that the contractor who must do most of task 203 is not the Prime at all. But, the prime needs to pass those requirements down to some key subcontractors who are doing the development stuff. So, it’s not a given that the prime contractor right underneath the customer must do all this stuff. It may have to be done at several different levels.

And again, we’ve got to provide the concept of operations (E.), that gives the context for all this work. Otherwise, it gets very difficult to do it. You’ve got to say, ‘What’s the jurisdictional context?’ ‘Where will we be operating under?’ ‘Which rules and conditions?’ As well as everything else that you would find in Con. Ops (Concept of Operations).

And then if there are any specific hazard management requirements (F.) that need to be imposed and specific measures of risk, then they need to be passed on to the contractor as well. This is how we will assess, and measure, and prioritize risks. That needs to be done for the program otherwise, you can end up with lots of different ways doing it and it becomes difficult to govern mess.

Section 4.2 #1

I promised we would have a little section on Section 4.2 in the standard and I’ve got two slides here that say two important things. We’re not going to go through all of Section 4 of the 882- That’s for another session. But here in 4.2, we’ve got two important things.

It says Section 4 defines system safety requirements through life for any system. And when properly applied, these requirements should enable the identification and management of hazards and their associated risks. Not only during system development but also during sustainment. And any engineering activities that go on in sustainment, whether it be repair, overhaul, modification, update, whatever it might be. These requirements are put in place to enable that good work to take place and make predictions for the through-life operation, support, sustainment of system, whatever it might be.

Section 4.2 #2

And then secondly, there’s another important point here, which I alluded to earlier. System safety staff are not responsible for hazard management in other functional disciplines. If you’re a structural designer, you’re responsible for making your structure or designing your structure such that risks of failure and collapse and catastrophe are managed. And the same for everything else. Whatever it is you’re dealing with, propulsion, fuels, you name it, whatever the discipline is, they’re all responsible for managing the risks.

The safety team are there really to pull it together and try and ensure some consistency and honesty and to report status. They are not there to do it all for the designers. Indeed, they can’t because they will not have the design specialist knowledge to do so. Only the designers can do. But it does go on to say all functional disciplines, using this generic methodology that’s in Section 4, should coordinate their efforts as part of the overall systems engineering process. The standard provides standardization and it should force all these different disciplines to work together in a standardized way following a standardized-systems-engineering process. And remember we said earlier, Mil. standard 882 assumes that there is a higher-level systems-engineering process going on into which the safety program fits. And that’s very, very important.

On so many programs I’ve seen, there’s either no systems engineering process or a weak one. Or the safety program is divorced or isolated from the systems engineering, the higher-level program, and as a result, it can become irrelevant if you’re not careful. So, having these things and making sure that they lock together is very important. And the reasoning given here is because you might mitigate a hazard in one discipline only to make it worse for somebody else. We can all think of examples of one (which is code for me saying I can’t right now). But anyway, trade-offs – that’s what we end up with. There’s Section 4.2, which gives us a little insight into the thrust of the whole of section 4.

Commentary #1

Just two slides of commentary for me. First, it’s worth remembering that there are lots, and lots, and lots of requirements. We’ve got requirements of the standard itself, which is about following a rigorous process. We’ve got law at international and national level, and whether those laws apply in a particular jurisdiction or not can be complex. You’ve got product specifications; you’ve got applicable standards, or maybe only parts of the standards that are applicable to your system. And then you’ve got program project requirements, etc., etc. You’ve got lots and lots of layers of requirements that are out there and may or may not be relevant to your system you want to develop, or service, whatever it is going to be. But of course, if we’re using this kind of approach, it’s going to be a complex system or service. It’s going to be challenging to find and identify all these things. It’s going to take some dedicated effort.

That’s one issue, doing all that work. And this is not a trivial exercise and I’ve seen it done badly far more often than I’ve seen it done well. That’s the thing to bear in mind, this is not easy to do. And people didn’t really want to do it – it’s hard work.

And then secondly, we get down to what we might call derived safety requirements. We have a high-level requirement that says, ‘We want a very high level of performance out of this vehicle’ or whatever it might be. And that very demanding performance requirement might force us to use some very high energy fuel, or it might force us to pack a lot of power and a lot of equipment into a very small space, and these requirements can lead to sort of secondary hazards. So, we’ve got high energy fuel inside the vehicle- Well, clearly, that’s dangerous if it leaks. We’ve got a lot of stuff, complex stuff, packed into a small system that can give us thermal control problems. Or if a bit of it goes wrong, if it’s tightly packed together, it can take out something else next to it.

So, these performance requirements can cause hazards that probably weren’t there before or needn’t have been there in, let’s say, a common or garden system that doesn’t have to perform as well. So, we might well look at doing some analysis on our requirements and our top-level design or conceptual design, whatever it might be very early on. And we might say, ‘Well, clearly this is going to drive us down a particular path’ and therefore we will derive some additional safety requirements to deal with these challenges. They don’t come out straight out of higher-level requirements, they’re a secondary effect. But in complex systems, these are very common. And if we’re doing our systems engineering well, we will identify, derive safety requirements for ourselves and for the next level of contractors down the chain.

So, instead of just passing on ‘back-to-back’ requirements from the ultimate customer, which may not mean anything at all to the component supplier (in fact, it probably won’t). We need to change these top-level requirements and say, ‘What’s relevant for you as the supplier role of the engine?’ Let’s say or the wheels, or the wings, or the hull, or whatever it might be. We need to pass on required controls, whether it be prevention of hazards, detection or mitigation. We also need to remember the order of precedence. It’s preferable to eliminate hazards if we can’t, we put in engineering- engineered features- to reduce the risk or lessen the probability, or severity, etc. And those rules are in section 4.3.4 of the Mil. Standard. There’s a lot of work to do on requirements on many different levels and it may be that this task must be repeated at many different levels.

Commentary #2

But the first level task must be done by the client, and actually by the ultimate end-user because to mangle a famous quote, ‘What you don’t specify – what you don’t see can hurt you’. So, we need to do this work as end-users, and as purchases, as customers. It is tempting to assume that the contractors will just do it, that they’ll just get it. ‘They’ve been making planes for years’ or ‘They’ve been making tanks’, or boots, or guns, or ships, or whatever it might be. ‘They’ve been making fuel for years’, ‘these chemicals for years’. We just assume that they know what they’re doing. Well, they probably do know what they’re doing within a particular context. However, if we impose competition, as we always do because we’re always looking for value for money, and whether we have a competition where we’re asking for a firm price to do something or whether we employ other methods of competition and cost-cutting, that will always be pressure on the contract costs. And that means they will be tempted to tailor the safety approach they’re taking in order to reduce costs. Which is a perfectly legitimate thing to do, nothing immoral about doing that, if it’s done appropriately and sensibly.

But if you as the customer or client are going to incentivize your suppliers to do that, you need to be aware of that and the fact that may just not bother because you haven’t told them to. You’re not contractually specified it so you aren’t going to get it. It’s not their problem. And indeed, the suppliers may not understand how their customer will integrate what they provide or use it. The prime contractor may not have a great idea as to how you’re going to use their product. And you can be certain that the subcontractors and the low level secondary and tertiary suppliers are probably going to have no clue whatsoever about what’s going to happen to their components. They are just not going to know. So, you need to specify that as purchaser and you need to make sure that your immediate suppliers pass on those requirements and that context and that they police contract appropriately. Otherwise, there’s going to be trouble for the ultimate client and end-user.

And then finally, in these days of globalization and business-to-business and international procurement, you may be – probably are – buying stuff that’s been made abroad and designed in another country where they may have completely different laws or no laws at all on how safety is built-in – designed in – to a system. And of course, you don’t always know where design work is going to get done; just because you engage a prime contractor in your own country and think that you’re safe. You don’t know whether the prime contractor is going to subcontract software development – let’s say, out to India. It’s so common it’s a cliché! But there are certain things that tend to be done offshore because it’s cheaper, or quicker, or whatever. Or because somebody has already got a system that you can just plugin and use – allegedly.

There’s all kinds of reasons why your supply chain will not necessarily ‘Just get it’, or ‘Just do it”’. In fact, there’s lots of good reasons why they won’t. So, the purchaser has got to do a lot of work and it’s critical for the purchaser to know what their obligations are, because a lot of purchasers don’t. They sit there in blithe ignorance of what their safety responsibilities are, and the lucky ones get away with it. And the unlucky ones are either killed or maimed, or they kill or maim somebody else and they end up going to jail or massive fines. But you’ve not only got to understand the requirements, the obligations, safety on the end item being used but how do you translate that to the contractors, because it’s not always obvious. You can’t just say, ‘Well, these are the laws that I have to obey- I’ll just pass those on to you, Mr Contractor’ because they may not apply to the contractor if they’re in a different country.

Or it just may not make any sense at their level. Laws that were designed to protect people will not often make much sense to a component supplier. Just doesn’t work. Two important points there on the commentary. Lots of layers of requirements that need to be worked on. This is all classic systems engineering stuff, isn’t it? And then the purchaser and the end-user cannot evade their responsibilities at the top of the food chain. Indeed, they’ll be stuck with the problem, whatever it is, for 30 years or however long they use the system.

It’s important for the end-user and the ultimate client to do this work may be several times at many different layers.

Copyright Statement

Well, that’s the end of the technical content. I just wanted to say that I’ve quoted a lot of text from the Mil, standard, which is itself copyright-free, and it’s available for free online, including on the Web site the Safety Artisan. But this presentation’s copyright of the Safety Artisan 2020.

For More …

And for more resources and for more videos like this one, please go to www.safetyartisan.com.

End

Well, that is the end of the presentation. And it just remains for me to say thanks again for watching and do lookout for the next sessions in the series on 882 echo (882E). There are quite a few to go. We’re going to go through all the tasks and the general and specific requirements of the standard and the appendices. We will also talk about more advanced topics, about how we manage and apply all this stuff.

So, from The Safety Artisan, thanks very much and goodbye.

End: System Requirements Hazard Analysis

You can find a free pdf of the System Safety Engineering Standard, Mil-Std-882E, here.

Categories
Mil-Std-882E Safety Analysis

Preliminary Hazard Identification

Want to know how to perform Preliminary Hazard Identification?  This is the first step in safety assessment.  We look at three classic complementary techniques to identify hazards and their pros and cons.  This includes all the content from Task 201, and also practical insights from my 25 years of experience with Mil-Std-882. 

This is the seven-minute-long demo video.

Topics: Preliminary Hazard Identification

  • Task 201 Purpose & Task Description;
  • Historical Review;
  • Recording Results;
  • Contracting; and
  • Commentary:
    • Historical Data;
    • Hazard Checklists; and
    • Analysis Techniques.
Transcript: Preliminary Hazard Identification

Hello, everyone, and welcome to the Safety Artisan, where you will find instructional materials that are professional, pragmatic and impartial, because we don’t have anything to sell and we don’t have an axe to grind. Let’s look at what we’re doing today, which is Preliminary Hazard Identification. We are looking at one of the first actual analysis tasks in Mil-Std-882E, which is a systems safety engineering standard from the US government, and it’s typically used on military systems, but it does turn up elsewhere.

Preliminary Hazard ID is Task 201

I’m recording this on the 2nd of February 2020, however, the Mil-Std has been in existence since May 2012 and it is still current, it looks like it is sticking around for quite a while, this lesson isn’t likely to go out of date anytime soon.

Topics for this session

What we’re going to cover is, quoting from the task, first of all, we’re going to look at the purpose and the task description, where the task talks quite a lot about historical review (I think we’ve got three slides of that), recording results, putting stuff in contracts and then I’m adding some commentary of my own. I will be commenting all the way through, that’s the value add, that’s why I’m doing this, but then there’s some specific extra information that I think you will find helpful, should you need to implement Task 201. In this session, we’ve moved up one level from awareness and we are now looking at practice, at being equipped to actually perform safety jobs, to do safety tasks.

Preliminary Hazard Identification (T201)

The purpose of Task 201 is to compile a list of potential hazards early in development. two things to note here: it is only a list, it’s very preliminary. I’ll keep coming back to that, this is important. Remember, this is the very first thing we do that’s an analytical task. There are planning tasks in the 100 series, but actually, some of them depend on you doing Task 201 because you can’t work out how are you going to manage something until you’ve got some idea of what you’re dealing with. We’ll come back to that in later lessons.

It is a list of potential hazards that we’re after, and we’re trying to do it early in development. And I really can’t over emphasize how important it is to do these things early in development, because we need to do some work early on in order to set expectations, in order to set budgets, in order to set requirements and to basically get a grip, get some scope on what we think we might be doing for the rest of the program. this is a really important task and it should be done as early as possible, and it’s okay to do it several times. Because it’s an early task it should be quick, it should be fairly cheap. We should be doing it just as soon as we can when we’re at the conceptual stage when we don’t even have a proper set of requirements and then we redo it thereafter maybe. And maybe different organizations will do it for themselves and pass the information on to others. And we’ll talk about that later as well.

the task description. It says the contractor shall – actually forget about who’s supposed to do it, lots of people could and should be doing this as part of their project management or program management risk reduction because as I said, this is fundamental to what we’re doing for the rest of the safety program and indeed maybe the whole project itself. So, what we need to do is “examine the system shortly after the material solution analysis begins and compile a Preliminary Hazard List (PHL) identifying potential hazards inherent in the concept”. That’s what the standard actually says.

A couple of things to note here. Saying that you start doing it after material solution analysis has begun might be read as implying you don’t do it until after you finish doing the requirements, and I think that’s wrong, I think that’s far too late. to my mind, that is not the correct interpretation. Indeed, if we look at the last four words in the definition, it says we’re “identifying potential hazards inherent in the concept”. that, I think, gives us the correct steer. we’ve got a concept, maybe not even a full set of requirements, what are the hazards associated with that concept, with that scope? And I think that’s a good way to look at it.

Historical Review

This task places a great deal of emphasis on the review of historical documentation, and specifically on reviewing documentation with similar and legacy systems. an old system, a legacy system that we are maybe replacing with this system but there might be other legacy systems around. We need to look at those systems. The assumption is that we actually have some data from similar and legacy systems. And that’s a key weakness really with this, is that we’re assuming that we can get hold of that data. But I’ll talk about the issues with that when I get to my commentary at the end.

We need to look at the following (and it says including but not limited to).

a) mishap and incident reports, this is a US standard. they talk about mishaps because they’re trying to avoid saying accidents because that implies that something has gone wrong accidentally. Whereas the term mishap, I believe, is meant to imply that it might be accidental, it might be deliberate, whatever it might be, it doesn’t matter, something has gone wrong. An undesirable event has happened, it’s a mishap. we need to look at mishap and incident reports. Well, that’s great, if you’ve got them if they’re of good quality.

b) You need to look at hazard tracking systems. When the Mil-Std talks about hazard tracking systems it is referring to what you and I might describe as a hazard log or a risk register. It doesn’t really matter what they called, where are you storing information about your hazards? And indeed, the tracking implies that they are live hazards, in other words, associated with a live system and things are dynamic and changing. But don’t worry about that, you should, we should, be looking in our hazard logs, in our risk registers, that kind of thing.

c) Can we look at lessons learned? Fantastic, again, if we’ve got them. But unfortunately, learning lessons can be a somewhat political exercise, unfortunately. it doesn’t always happen.

d) We need to look at previous safety analyses and assessments. That’s fantastic. If we’ve got stuff that’s even halfway relevant, maybe we could use it and save ourselves a lot of time and trouble. Or maybe we could look at what’s around and go, actually, I think that’s not suitable because…, and then even that gives you a steer to say, we need to avoid what’s gone wrong with the previous set of analysis. But hopefully without just throwing them out and dismissing them out of hand, because that’s far too easy to do (not invented here, I didn’t do it, therefore it’s no good). Human pride is a dangerous thing.

e) It says health hazard information. Maybe there are some medical results, some toxicology, maybe we’ll be tracking the exposure of people to certain toxins in similar systems. What can we learn from that?

f) And test documentation. let’s look at these legacy systems. What went right, what didn’t go right and what had to be done about it. all useful sources of information.

g) And then that list continues. Mil-Std 882 includes environmental impact, its safety, and environmental impact is implicit all the way through the standard. we also need to look at environmental issues, thinking about system testing, training, where it’s going to be deployed, and maintenance at different levels. And we talk about potential locations for these things because often environmental issues are location sensitive. doing a particular task in the middle of nowhere in a desert, for example, might be completely harmless, doing it next to a significant watercourse, which is near a Ramsar Wetland (an environment of international importance) or an area of outstanding natural beauty or a national park, something like that, might have very different implications. it’s always location-sensitive with environmental stuff.

h) And being an American publication, it goes on to give a specific example: The National Environmental Policy Act (NEPA), which is in the U.S. and then similarly there is an executive order looking at actions by the federal government when abroad and how the federal government should manage that. Now, those are U.S. examples. If you’re not in the U.S. there’s probably a local equivalent of these things. And certainly, I live and work in Australia, we have an Australian Environmental Protection and Biodiversity Conservation Act (AEPBC), and that equivalent of it, it doesn’t just apply in Australia, it also applies to what the Commonwealth Government does abroad as well. outside the normal Australian jurisdiction, it does apply.

i) And then finally, we’ve got to think about disposing of the kit. Demilitarisation: maybe we’re going to take out the old military stuff and flog it to somebody, we need to think about the safety and environmental impacts of doing that. Or maybe we’re just going to dispose of the kit, whatever it might be, we’re going to scrap it or destroy it or put it away somewhere, store it again in the desert somewhere for a rainy day. If that’s not a contradiction in terms. we’re going to think about the disposal of it as well and what are the safety and environmental implications of doing so? there’s a good, broad checklist here to help us think about different issues.

Recording Results

It says that, whoever is doing this stuff, the contractor, shall document identified hazards in this hazard tracking system, in this hazard log, this risk register, whatever you want to call it. And the content of this recording and the formats to be used have got to be agreed between, it says the contractor and the program office, but generally the purchaser and whoever is doing the work. the purchaser might also be the ultimate end-user, as is often the case with the government, or it might be something else. Again, it might be the purchaser who will sell on to an end-user, but they’ve got to agree what they’re going to do with the contractor.

And of course, doing so, you’ve got to understand what your legal obligations are. Again, for example, in Australia, the WHS Act puts particular obligations on designers, manufacturers, suppliers, importers, etc. There are three duties and two of them are associated with passing on information to the end-user. be aware of what your obligations are, the kind of information that at a minimum you must provide, and probably make sure that you’re going to get, that minimum information in a usable format and maybe some other stuff as well that you might need. And it says unless specified elsewhere, in other words, by agreement with the government or whoever is the purchaser, you’ve got to have a brief description of the hazard and the causal factors associated with each identified hazard.

Now this is beginning to get away from just a pure list, isn’t it? it’s not just a list, we have to have a description that we can scope out the hazard that we’re talking about. Bear in mind, early on we might identify a lot of hazards that subsequently actually turn out to be just one hazard or are not applicable or are covered by something else. we need a description that allows us to understand the boundaries of what we’re talking about. And then we’re also being asked to identify causes or causal factors. maybe circumstances, what could cause these things, etc. it’s a little bit more than just a list, but we’re beginning to fill in the fields in the hazard log as we do this at the start.

Contracting

Now, this is very useful, in the standard for every task it says here are the details to be specified in the contractual documentation, and notice it says details to be specified in the Request for Proposal. you’ve got to ask for this stuff if you need it. You’ve got to know that you need it and why you need it and what you’re going to do with the information as a purchaser. And you’ve got to put that in right at the start in the Request for Proposal and the Statement of Work. And here’s some guidance on what to include.

The big point here is this needs to be done very early on. In fact, to be honest, the purchaser is going to have to do Task 201 themselves and maybe some other tasks in order to get enough data and enough understanding to write the Request for Proposal and the Statement of Work in the first place. you do it yourself and then maybe you do a quick job to inform your contracting strategy and what you’re going to do and then you get the contractor to do it as well.

What have we got to include? Well, we’ve got to impose Task 201. I’ve seen lots of contracts where they just say, ah, do safety, do safety in accordance with this standard, do Mil-Std 882, or whatever it might be. And a very broad open-ended statement like that is vulnerable to interpretation because what your contractors, your tenderers, will do is in order to come in at the minimum price and try and be competitive is they will tailor the Mil-Std and they will chop out things that they think are unnecessary, or that they can get away without doing and they might chop out some stuff that actually you find that you need. That can cause problems.

But even worse, if you’ve got a contractor who doesn’t understand how to do system safety engineering, who doesn’t understand Mil-Std 882, they might just blindly say, oh, yeah we’ll do that, and the classic mistake is you get in the contract, it says do Mil-Std 882E and here are all the DIDs, data item descriptors which describe what’s got to be in the various documents that the contractor has to provide. And of course, government projects love having lots of documentation, whether it’s actually helpful or not.

But the danger with this is this can mislead the contractor because if they don’t understand what a system safety program is, they might just go, I’ve got to produce all these documents, yeah, I can do that and not actually realize that they’ve got to do quite a lot of analysis work in order to generate the content for those reports. And I know that sounds daft, but it does happen, I’ve seen it again and again. You got a contractor who produces these reports that on paper have met the requirements of the DID because it’s got all the right headings, it’s got all the right columns, or whatever else. But it’s full of garbage information or TBD or stuff that is obviously rubbish. And you think, no, no, you actually have to specify, you need to do the task and the documentation is the result of the task. we don’t want the tail wagging the dog. Anyway, I’ll get off my soapbox. You’ve got to impose the task, it’s a job to be done, not just a piece of paper to be produced.

Identification of the functional disciplines to be addressed. who’s going to be involved? What are you including? Are you including engineering, maintenance, human factors? Who’s got to be involved? Ideally, you want quite a wide involvement, you want lots of stakeholders, which you need to think about.

Guidance on obtaining access to government information. Now, whether it’s the government or whoever the purchaser is, it doesn’t have to be a government, getting a hold of information and guidance out of the purchaser can be very difficult. And very often that’s because the purchaser hasn’t done their homework. They haven’t worked out what information they will need to provide because maybe they don’t understand the demands of the task or they’ve just not thought it through, quite frankly. And the contractor or whoever is trying to do the analysis finds that they are hamstrung, they can’t actually do the work without the information provided by the purchaser.

That means the contractor can’t do the work, and then they just pass the risk straight back to the government, back to the purchaser, and say: I need this stuff. And then the purchaser ends up having to generate information very quickly at short notice, which is never good, you never get a quality result doing that. And often my job as a consultant is I get called in by the purchaser as often as I do by the supplier to say help, we don’t know what’s going on here, the contractor has said I can’t do the safety program without this information and I don’t understand what they want or what to tell them. as a consultant, I find myself spending a lot of time providing this kind of expertise because either the purchase or contractor doesn’t understand their obligations and hasn’t fulfilled them. Which is great for me, my firm gets paid a lot of money. It’s not good for the safety program.

Content and format requirements. Yes, we need to specify the content that we need. I say need not want. What are we going to do with this stuff? If we’re not going to do anything with it, do we actually need it at all? And what’s the format requirements? Because maybe we need to take information from lots of different subcontractors and put it all together in a consistent risk register. if it comes in all different formats, that’s going to make a lot more work and it may even make merging the information impossible. we need to think about that.

Now, what’s the concept of operations? We’ll come back to that in later tasks. But the concept of operations is, what are we going to do with this system? that should provide the operating environment. It should provide an overview of some basic requirements, maybe how the system will interface with other systems, how it will interact, concepts of operation deployment basing, and maintenance. And maybe they’re only assumptions at this stage, but the people doing the analysis will need this stuff. You recall the environmental stuff is very location-sensitive, we need a stab at where these things will happen and we need to understand what the system is going to be used for because in safety, context is everything. A system that might be perfectly safe in one context, if it’s being used not for what it was originally designed for or conceived for, can become very dangerous without anybody realizing.

Other specific hazard management requirements. What definitions are we using? Very important because again, it’s very easy to get different information that’s being generated against different definitions by different contractors. And then it’s utter confusion. Can we compare like with like, or can’t we? What risk matrix are we going to use on this program? What normally happens on 882 programs is people just take the risk matrix out of the standard and use it without changing it. Now, that might be appropriate in certain circumstances, but it isn’t always. But I’m going to talk about that, that’s a very complex, high-level management issue and I’m going to be talking about that in a separate issue about how do we actually derive a suitable risk matrix for our purposes and why we should do so. Because the use of an unsuitable matrix can cause all sorts of problems downstream, both conceptual problems in the way that we think about stuff and lower levels, sort of mechanistic problems. But I don’t have time to go into that here.

Then references and sources of hazard identification. This is another reason why the purchaser needs to have done their homework. Maybe we want the contractor or whoever is doing the analysis to look at particular sources of information that we consider to be relevant and necessary to consider. we need to specify that and understand what they are. And usually we need to understand why we want them as well.

Commentary

That’s what was in the standard, as you see it’s very short, is only a page and a half in the standard and it is quite a light, high-level definition of the task because it’s an early task. Now let’s add some value here. Task 201 goes talks all about historical data. However, that is not the only way to do preliminary hazard identification. There are in fact two other classic methods to do PHI. One is the use of hazard checklists and you can also use some simple analysis techniques. And we need to remember that this is preliminary hazard identification, we’re doing this early and often to identify as many hazards as possible to find those hazards and the associated causes, consequences, maybe some controls as well. we’re trying to find stuff, not dismiss it or close out the hazards. And again, I’ve seen projects where I’ve read a preliminary hazard identification report and it says, we closed 50 hazards, and I think, no, you didn’t, you weren’t supposed to close anything because this is preliminary hazard identification. You identify stuff and then it gets further analyzed. And if upon analysis, you discover actually this hazard is not relevant, it cannot possibly happen, then, and only then, can you close it. Let’s remember, this is a preliminary hazard ID.

Commentary – Historical Data

First of all, let’s look at historical data. And first of all some issues with using this historical data, availability. Can we actually get hold of it? Now, it may be that you work for a big corporate or government organization that for whatever reason has good record keeping and you’ve got lots and lots of internal data that is of good quality that you’re allowed to access and that you know about and you can find or discover. If you are one of those people who are very, very lucky, you are in a minority, in my experience. If you’ve got all that stuff, fantastic, use it. But if you haven’t or if the information is of poor quality or people won’t give you access for whatever reason. And there are all sorts of reasons why people want to conceal information, they’re frightened of what people may discover, especially safety engineers. You may have to go out to external sources.

Now, the good news is that in the age of the Internet, getting hold of external data is extremely easy. there’s lots of potential sources of data out there, and it may range from stuff on Wikipedia, public reporting of accidents and incidents by regulators or by trade associations or by learned societies that study these things or by academics or by consultancy such as the one that I work for. there’s all kinds of potential sources of information out there that might be relevant to what you’re doing. And even if you’ve got good internal information, it’s probably worth searching out there for what’s external as a due diligence exercise, if nothing else, just to show that you haven’t just looked inwardly, that you’ve actually looked outwardly the rest of the world. There are lots of good sources of information out there. And depending on what industry you’re in, what domain you work in, you will probably know some of the things that are relevant in your area.

Now, just because data is available doesn’t mean that it’s reliable. It might be vague or inconsistent. We’ll come onto that later. It might be patchy. It’s usual for incidents to be underreported, especially minor incidents. you will find often that the stuff that gets reported is only the more serious stuff, and you should really assume that there has been under-reporting unless you’ve got a good reason not to. But to be honest, underreporting is the norm almost everywhere. there’s the issue of reliability, the data that you’ve got will be incomplete.

Secondly, another big issue is consistency. People might be reporting mishaps or incidents or accidents or events or occurrences. They might be using all sorts of different terminology to describe stuff that may or may not be relevant to what you’re talking about. And there’s lots of information out there, but actually, how has it been classified? Is it consistent? Can you compare all these different sources of information? And that can be quite tricky. And very often because of inconsistencies in the definition of a serious injury, for example, you may find that all you can actually compare with confidence is fatalities because it’s difficult to interpret death in different ways. As a safety engineer, frequently I start with fatal accidents, if there are any, because those can’t be misinterpreted. And then you start looking at serious injuries, minor injuries, incidents where no one gets hurt, but somebody could have been. There are all sorts of pitfalls with the consistency of the data that you might get a hold of.

There’s relevance. It may be that you’re looking at data from a system that superficially looks similar to yours, but with a bit of digging, you may discover that although the system was similar, it’s being used in a completely different context and therefore there are significant differences in the reporting and what you’re seeing. there may be data that is out there, but just not relevant for whatever reason.

And finally, objectivity. Now, this is a two-way street. Historical data is fantastic for objectivity because it stops people from saying subjectively, this couldn’t possibly happen. And I’ve heard this many times, you come up with something and somebody said, oh that couldn’t possibly happen, and then you show them the historical evidence that says, well it’s happened many times already and then they have to eat their words. Historical data is fantastic for keeping things objective, provided of course, that it’s available, reliable, consistent, and relevant. you’ve got to do a bit of work to make sure that you’re getting good data, but if you can, it’s absolutely worth its weight in gold, not just for Hazard I.D., but for torpedoing some of the stupid things that people come out with when they’re trying to stop you doing your job for whatever reason. historical data is great for shooting down prejudice is basically what I’m saying. reality always wins. That’s true in safety in the real world and in the safety analysis.

Having said all that, what’s the applicability of historical data? It may be that really we can only use it for preliminary hazard identification and analysis. (I’ve just noticed I’ve got preliminary hazard identification and analysis.) Sometimes I see contractors try to use historical data to say, that’s the totality of my safety argument, my kit is wonderful, it never goes wrong and therefore it will never go wrong, that’s the totality of my safety argument. And that never works, because when you start trying to use historical data as the complete safety argument, you very quickly come up against these problems of availability, reliability, consistency, and relevance.

It’s almost impossible to argue that a future system will be safe purely because it’s never gone wrong in the past. And in fact, trying to make such claims as, it’s never gone wrong, we’ve never had a problem, we’ve never had an incident, straight away that would suggest to me that they don’t have a very good incident reporting system or that they’ve just conveniently ignored the information they do have and not that people selling things ever do anything like that? Of course, no, never. There’s a lot of used car salesmen out there. probably this use of historical data, we might have to keep it fairly limited. It might be usable for preliminary work only. And then we have to do the real work with analysis. But almost certainly it’s not going to be the whole answer on its own. do bear that in mind, historical data has its limits.

It’s also worth remembering that we get data from people as well. In Australia, the law requires managers to consult with workers in order to get this kind of information. No doubt in other countries there are similar obligations. there’s lots of people out there, potentially workers, management, suppliers and users, maintainers, regulators, trade associations, lots of people who might have relevant information. we really ought to consult them if we can. Sometimes that information is published, but other times we have to go and talk to people or get them to come to a preliminary hazard I.D. meeting in order to take part. There are lots of good ways of doing this stuff.

Commentary – Hazard Checklists

Let’s move on to hazard checklists. Checklists are great because someone else has done the work for you to a degree that it’s quick and cheap to get a checklist from somewhere and go through it to see if you can find anything that prompts you to go, yeah that could be an issue with my system. And the great thing about checklists is they broaden the scope of your hazard I.D. because if your historical data is a bit patchy or a bit inconsistent as it often is, it will identify some stuff, but not everything. the great thing about a checklist is very often broad and shallow, it really broadens the scope of the hazard I.D., it complements your historical data. I would always recommend having a go with a checklist.

Now, bear in mind that checklists tend to identify causes, you then have to use some imagination to go, okay, here’s a cause, how in the context of my system, how in the context of this concept of operations (very important), in this context, how could that cause lead to a hazard and maybe to a mishap? you need to apply some imagination with your checklist and it can be a good way of prompting a meeting of stakeholders to think about different issues because people will turn up with an axe to grind, they’ll have their favourite thing they want to talk about. Having a checklist keeps it objective or having historical data to review, keep it objective, and keeps people on track, so they don’t just go down a rabbit hole and never look at anything else.

But again, this is preliminary hazard identification only. if something comes up, I would advise you to take the position that it could happen unless we have evidence that it could not. And notice, I say evidence, not opinion. I’ve met plenty of people who will swear blind, that such and such could not possibly happen. A classic one that suckered me, somebody said no British pilot would ever be stupid enough to take off with that problem, and like a fool, I believed them. Don’t listen to opinion, however convincing it is unless there’s evidence to say it cannot happen because it will. And in that case, it did two weeks later. don’t believe people when they say, oh that couldn’t possibly happen, it just shows a lack of imagination. Or they’ve got some vested interests and they’re trying to keep peace and keep you away from something.

It’s worth mentioning, in Australia at minimum, we need to use the approach for Hazard I.D. that is in the WHS Risk Management Code of Practice. there’s some good basic advice in that code of practice on what to do to identify and analyse hazards and assess risks and manage them. We need to do it, at minimum. It’s a good way to start, and in fact there’s a bit of a hazard checklist in there as well. It’s not great, it’s workplace stuff mainly rather than design stuff or systems engineering stuff. But nevertheless, there’s some good stuff in there and that is the absolute bare minimum that we have to do in Australia. And there will probably be local equivalents wherever you are.

If you’re looking for a good example for a general checklist, if you look in, the U.K.’s ASEMS, which is the MOD acquisition safety and environmental management system. In POSMS, which is the project-oriented safety management system, there is a safety management procedure, SMP04, which is PHI. And that’s got a checklist in there. It’s aimed at sort of big equipment, military equipment, but there’s a lot of interesting stuff in there that you could apply to almost anything. If you look online, you’ll probably find lots of checklists, both general checklists and specialist checklists for your areas, maybe your trade association, or whatever has a specialist checklist for the particular stuff, the thing that you do. always good to look up those things online, and see if you can access them and use them. And as I say, using multiple techniques helps us to ensure or have confidence that we’ve got fairly complete coverage, which is something that we’re going to need later on. And dependent on your regulator, you might have to demonstrate that you’ve done a thorough job, using multiple techniques is a good way of doing that. I’ve already said checklists nicely complement historical data because they’ve got different weaknesses.

Commentary – Analysis Technique

A third technique, which again takes a different approach, it complements the other two, is to use some kind of analysis technique to identify hazards. And there are lots of them out there. Again, I’m not going to go into them now in this session, I’m just going to give you one example, which is probably the simplest one I know, and therefore the most cost-effective. And you can do this as a desktop exercise and then get some stakeholders in and do it live with the stakeholders. Either use what you’ve prepared, or keep what you’ve prepared in your back pocket if you need to get things going, if people are stumped, they’re not sure what to do.

Now, this technique I’m just going to talk about is called Functional Failure Analysis (FFA). And really all it does, you take a basic top-level function of whatever it is that you’re considering, you’ve got your concept of operations that says, I need a system to do X, Y, Z, you go, let’s look at X, Y, and Z, and with each one of these functions, what happens if it doesn’t work when it’s supposed to work, or what happens if it works when I don’t want it to? That’s the un-commanded function or unwanted function, maybe. And then what if it happens, but it doesn’t happen completely correctly. What if it happens incorrectly? And there might be several different answers to that.

I’ll give you an example. Let’s assume that you’re Mr. Mercedes, and you’re inventing the horseless carriage, you’re inventing the automobile, the car. And you say, this thing, it’s got a motor, I wanted it to start off, I want it to go and then I want to stop. those really, really simple conceptual ideas, I want it to go, or I want it to start moving. What happens if it doesn’t? Well, nothing actually, from a safety point of view. The driver might be a bit frustrated, but it’s not going to hurt anybody. Next, an un-commanded function: what if it goes when it’s not supposed to? Now that’s bad. Or maybe the vehicle will roll away downhill when it’s not supposed to. We need a parking brake, in that case, we need a handbrake or use chocks or something or we restrain it.

Straight away, with something as simple and simplistic as this, you can begin to identify issues and say, we need to do something about that. this is a really powerful technique, you get a lot of bangs per buck. And then, of course, we could go on with the example, it’s a trivial example, but you can see potentially how powerful it is providing you’re prepared to ask these open-ended questions and answer them imaginatively without closing your mind to different possibilities. there’s an example of an analysis technique, and again, remember that this preliminary hazard ID. If we’ve identified something that could happen, then it could happen unless we have evidence that it could not.

I’ve talked for long enough, it just remains for me to point out that the quotations from Mil-Std are copyright free. But this video is copyright of The Safety Artisan 2020. And you can find more safety information, more lessons, and more safety resources at www.safetyartisan.com. I just want to say that’s the end of the lesson, thank you very much for listening and I hope you’ve found today’s session useful. Goodbye.

End: Preliminary Hazard Identification

You can find a free pdf of the System Safety Engineering Standard, Mil-Std-882E, here.

Categories
Work Health and Safety

Intro to Work Health and Safety

This short video Intro to Work Health and Safety looks at Australian legislation that is relevant to System Safety. Thus, it is of interest to system, functional and design safety practitioners.  It looks at the three classes of ‘upstream’ safety duties of designers, that also apply to manufacturers, importers, suppliers those who install/commission plant substances and structures. 

Intro to Work Health and Safety: so What?

Many people think the WHS Act only applies to the management of safety in the workplace. They’re wrong – it does much more than that. In this short presentation, I am going to show you why the WHS Act is relevant to those with ‘upstream’ safety responsibilities such as designers.

Intro to Work Health and Safety: Topics

  • The primary duty of care;
  • Safety duties of designers (Section 21); and
  • Similar duties apply to others, such as:
    • Manufacturers (Section 23);
    • Importers (Section 24);
    • Suppliers (Section 25);
    • Those installing, constructing or commissioning (Section 26);
    • Officers (Section 27); and
    • Workers (Section 28).

Intro to Work Health and Safety: Transcript

Click Here for the Transcript

Hi everyone and welcome to the Safety Artisan where you will find Professional, pragmatic And impartial Instruction on safety. Which we hope you enjoy. So today we’re talking about the Work Health and Safety (WHS) Act in Australia. Which is surprisingly relevant to what we do in Fact. Let’s see how surprising and relevant it is.

Were going to look at the WHS Act. And its relevance to what we’re talking about here on the Safety Artisan. And it’s important to answer that question first, The “So what” test. Many people think that the WHS Act is only applicable To safety In the workplace. So they see it as purely an occupational health and safety Piece of legislation.

And it isn’t!

It does do that, but it does so much more as well.
And in this short presentation, I’m going to show you why The WHS act is relevant. To system safety, functional safety, design safety, Whatever we want to call it.

Now I’m actually looking up some information On the work Health and Safety Act, from The Federal Register of Legislation. And, (In blue letters.) And if we go down to the bottom left-hand side of the screen. We will see
A little map of Australia with a big red tick on it. And in green, it says ‘in force latest version’. So I looked at the Website Today, the 6th of October. And this is the latest version. Which is just to make sure that We’ve got the right version. In Australia the Jurisdiction of which version of the act is in place Is complex. I’m not going to talk about that in the short session but I will in the full video version.

The Primary Duty of Care under the WHS Act

The Primary Duty of Care under the WHS Act is as follows. So a person Conducting a business or undertaking and – a Person Conducting a Business or Undertaking is usually abbreviated to PCBU. A horrible, horrible, clunky term! What it’s trying to say is whether you’re doing business or it is non-profit. Whether you work for the government. Or even if you’re self-employed. Whoever you are and whatever you do. If it’s to do with work, being paid for work. Then this applies to you.

Those people doing this stuff Are responsible For ensuring the health and
safety Of workers, who are engaged or paid by the person, by the PCBU. Workers whose activities are influenced or directed by the PCBU while they’re at work. And also the PCBU must ensure the health and safety of Other people. So in the vicinity of the workplace let’s say, or Maybe visitors.

As always the caveat on this ‘ensuring’ Health and Safety is ‘So Far As is reasonably Practicable’. Again we’re not going to be talking about So far as is reasonably practicable in this session, we’ll talk about it in the longer session; and, in fact, I think I’m probably going to do a session Just on the how to do So far as is Reasonably Practicable Because A lot of people Get it wrong. It’s quite a different concept. If you’re not used to it.

Designer Duties under the WHS Act

Moving on. We’ve jumped from Section 19 to Section 22. And we’re now talking about the duties of designers. Well, this doesn’t sound like occupational health and safety does it? So we look at the designer duties of PCBUs who design Plant, Substances, Or structures. So we’re talking industrial plant we’re not talking about commercial goods. There are other
Acts that apply to stuff that you would buy in a shop. So this is industrial plant, Chemical substances and the like. And structures and those might be buildings. Or they might be ships, floating platforms, whatever they might be. Aircraft. Cars.

The First WHS Duty of a Designer

So here we have The First Duty of a designer. And there are three groups of duties. First of all, The designer Has to ensure The health and safety of People in the workplace. If they’re designing plant. If they’re designing or creating. A substance, or A structure. That is to be used, Or might reasonably be expected to be used At a workplace. This duty applies to them. So they’ve got to do whatever it takes. To ensure Health and Safety So far as is reasonably practicable.

Now, carrying on from that. We get a bit more detail. So the designer has got to ensure, so far as is reasonably practicable, that plant, substance or structure Is designed To be without risks. The risks are To the health and safety of persons, who Are At a workplace. Who might, Use it For the purpose for which it was designed, Who might Handle the substance. Who might store the plant or substance? And who might construct a structure? Or, and here’s the catch-all, who might carry out any reasonably foreseeable activity At a workplace In relation to this plant, substance, or structure.

And then if we go on to Part (e)(i) And we now get a long list of stuff. Any reasonably foreseeable activity Includes manufacture, assembly, Use, Proper storage, decommissioning, dismantling, disposal, Etc. We run out of space there. But the bottom line is that the scope of this act is cradle to grave. So from the very first time that we Design A plant, substance or structure. Right through to final disposal of said, Plant Substance and structure. The Designer has safety responsibilities. Thinking about the whole lifecycle of This stuff.

The Second WHS Duty of a Designer

Now we move on to the other Two duties that a designer has. So in subsection 3. The designer has a duty to carry out testing. That’s what it says in the guide. Actually, if you look at the words in the act it says the designer must carry out or arrange for Calculations, analysis, testing, Or examination. Whatever is necessary for the performance of the duty that We just described In Subsection 2. You recall Subsection 2, cradle to grave, from creation to final disposal. Calculations, analysis, testing or examination Might be needed. The designer has got to Carry that out Or arrange it. In order to ensure safety SFARP.

The Third WHS Duty of a Designer

And then, our Final Duty Is having done all of that work. Having designed this stuff to be safe and done all the Calculations and testing. The designer must give Adequate information to each person provided with the design. And the purpose of doing so, We’re not just providing information for the sake of it, or because we felt like it. It’s provided for a specific purpose. So each Purpose, Which the plant, substance or structure was designed. So we need all the information associated With its design purpose.
We’ve got to provide the results of those calculations, analysis, testing and
examination.

And, Probably this is also equally Crucial from a hazard analysis point of view, Any conditions necessary to ensure that the plant, substance or structure Is without risk to health and safety. When it is used for the purpose for which it was designed, Or, (All the other stuff If we go back to
Section 2.)

So Section 4, Does actually say this applies to Section 2(a-e). But we ran out of space on the page, so the designers got to provide all the information necessary. for people to use this stuff and for the life cycle of whatever it is from cradle to grave. Now, If we look at Section 4(a-c), We can say that’s the kind of information we generate from Hazard Analysis from safety analysis. So, yeah, Absolutely We need system safety In order to meet these duties, to satisfy these duties.

A Consistent set of Duties Across the Supply Chain

And these duties are not just on designers, because the WHS Act Is actually Very, very clever. Because it applies Much the same duties, those three duties that we heard of. The duty to ensure health and safety. The duty to test and analyze. And the duty to provide information. If we look at Sections 22, Through 26, We find that very similar duties apply
To designers.
To manufacturers.
To importers.
To suppliers.
And to those installing, constructing, Or commissioning. Substances and
Structures.
And the duties in these sections are all consistent. Basically, it recognizes that there is a supply chain. From design right through to installation and commissioning. And Everybody in that chain Has duties To do their part correctly, or to test what they have to. Pass on information, To the next set of stakeholders.

And then, In addition to that, If we looked in Section 27 we would see the Officers Of the PCBU, so Company directors and the like, People with, major influence, Who are able to direct operations and that kind of thing. So senior management and directors of companies and the equivalent in the public sector Have special requirements applying to them. Again, We’re going to talk about that in the Main Video, Not in this one. And then workers have Duties to Comply with reasonable instructions, That are intended to keep safe And other workers [safe]. So that if we go to Section 28 you get the kind of thing that you would expect to see in work-place safety.

Copyright and Attribution

So that’s it In the short video. Just to mention that I have Shown you information From the Federal Register of Legislation. I’m entitled to do that under the Creative Commons license. And I’m making the required attribution statement. You can see it in the middle of the Screen. And for the full information on these terms on copyright and attribution, Please go to that page On my website. And you will find full details of the terms and conditions, under which this video was created. And if you want to see the full version of the introduction to the WHS Act, which is going to cover a lot more ground than this then please go to the Safety Artisan page On www.Patreon.com.

That’s the Presentation. And it just remains for me to say, Thanks very much for listening. I look forward to meeting you again. Cheers now.

The Full Version is Here…

If you want more, if you want a wider and deeper view of the WHS Act, then there’s a longer version of this video. Which you can get at my Patreon page.

I hope you enjoy it. Well that’s it for the short video, for now. Please go and have a look at the longer video to get the full picture. OK, everyone, it’s been a pleasure talking to you and I hope you found that useful. I’ll see you again soon. Goodbye.

The full-length ‘Guide to WHS’ video is here. Back to the WHS Topic Page.

Categories
Start Here System Safety

Safety Concepts Part 2

In this 33-minute session, Safety Concepts Part 2, The Safety Artisan equips you with more Safety Concepts. We look at the basic concepts of safety, risk, and hazard in order to understand how to assess and manage them. Exploring these fundamental topics provides the foundations for all other safety topics, but it doesn’t have to be complex. The basics are simple, but they need to be thoroughly understood and practiced consistently to achieve success. This video explains the issues and discusses how to achieve that success.

This is the three-minute demo of the full (33 minute) Safety Concepts, Part 2 video.

Safety Concepts Part 2: Topics

  • Risk & Harm;
  • Accident & Accident Sequence;
  • (Cause), Hazard, Consequence & Mitigation;
  • Requirements / Essence of System Safety;
  • Hazard Identification & Analysis;
  • Risk Reduction / Estimation;
  • Risk Evaluation & Acceptance;
  • Risk Management & Safety Management; and
  • Safety Case & Report.

Safety Concepts Part 2: Transcript

Click Here for the Transcript

Hi everyone, and welcome to the safety artisan where you will find professional, pragmatic, and impartial advice on safety. I’m Simon, and welcome to the show today, which is recorded on the 23rd of September 2019. Today we’re going to talk about system safety concepts. A couple of days ago I recorded a short presentation (Part 1) on this, which is also on YouTube.  Today we are going to talk about the same concepts but in much more depth.

In the short session, we took some time picking apart the definition of ‘safe’. I’m not going to duplicate that here, so please feel free to go have a look. We said that to demonstrate that something was safe, we had to show that risk had been reduced to a level that is acceptable in whatever jurisdiction we’re working in.

And in this definition, there are a couple of tests that are appropriate that the U.K., but perhaps not elsewhere. We also must meet safety requirements. And we must define Scope and bound the system that we’re talking about a Physical system or an intangible system like a computer program. We must define what we’re doing with it what it’s being used for. And within which operating environment within which context is being used.  And if we could do all those things, then we can objectively say – or claim – that the system is safe.

Topics

We’re going to talk about a lot more Topics. We’re going to talk about risk accidents. The cause has a consequence sequence. They talk about requirements and. Spoiler alert. What I consider to be the essence of system safety. And then we’ll get into talking about the process. Of demonstrating safety, hazard identification, and analysis.

Risk Reduction and estimation. Risk Evaluation. And acceptance. And then pulling it all together. Risk management safety management. And finally, reporting, making an argument that the system is safe supporting with evidence. And summarizing all of that in a written report. This is what we do, albeit in different ways and calling it different things.

Risk

Onto the first topic. Risk and harm.  Our concept of risk. It’s a combination of the likelihood and severity of harm. Generally, we’re talking about harm. To people. Death. Injury. Damage to help. Now we might also choose to consider any damage to property in the environment. That’s all good. But I’m going to concentrate on. Harm. To people. Because. Usually. That’s what we’re required to do. By the law. And there are other laws covering the environment and property sometimes. That. We’re not going to talk.  just to illustrate this point. This risk is a combination of Severity and likelihood.

We’ve got a very crude. Risk table here. With a likelihood along the top. And severity. Downside. And we might. See that by looking at the table if we have a high likelihood and high severity. Well, that’s a high risk. Whereas if we have Low Likelihood and low severity. We might say that’s a low risk. And then. In between, a combination of high and low we might say that’s medium. Now, this is a very crude and simple example. Deliberately.

You will see risk matrices like this. In. Loads of different standards. And you may be required to define your own for a specific system, there are lots of variations on this but they’re all basically. Doing this thing and we’re illustrating. How we determine the level of risk. By that combination of severity. And likely, I think a picture is worth a thousand words. Moving online to the accident. We’re talking about (in this standard) an unintended event that causes harm.

Accidents, Sequences and Consequences

Not all jurisdictions just consider accidental event some consider deliberate as well. We’ll leave that out. A good example of that is work health and safety in Australia but no doubt we’ll get to that in another video sometime. And the accident sequences the progression of events. That results in an accident that leads to an. Now we’re going to illustrate the accident sequence in a moment but before we get there. We need to think about cousins.  here we’ve got a hazard physical situation of state system. Often following some initiating event that may lead to an accident, a thing that may cause harm.

And then allied with that we have the idea of consequences. Of outcomes or an outcome. Resulting from. An. Event. Now that all sounds a bit woolly doesn’t it, let’s illustrate that. Hopefully, this will make it a lot clearer. Now. I’ve got a sequence here. We have. Causes. That might lead to a hazard. And the hazard might lead to different consequences. And that’s the accident. See. Now in this standard, they didn’t explicitly define causes.

Cause, Hazard and Consequence

They’re just called events. But most mostly we will deal with causes and consequences in system safety. And it’s probably just easier to implement it. Whether or not you choose to explicitly address every cause. That’s often option step. But this is the accident Sequence that we’re looking at. And they this sort of funnels are meant to illustrate the fact that they may be many causes for one hazard. And one has it may lead to many consequences on some of those consequences. Maybe. No harm at all.

We may not actually have an accident. We may get away with it. We may have a. Hazard. And. Know no harm may befall a human. And if we take all of this together that’s the accident sequence. Now it’s worth. Reiterating. That just because a hazard exists it does not necessarily need. Lead to harm. But. To get to harm. We must have a hazard; a hazard is both necessary and sufficient. To lead to harmful consequences. OK.

Hazards: an Example

And you can think of a hazard as an accident waiting to happen. You can think of it in lots of different ways, let’s think about an example, the hazard might be. Somebody slips. Okay well while walking and all. That slip might be caused by many things it might be a wet surface. Let’s say it’s been raining, and the pavement is slippery, or it might be icy. It might be a spillage of oil on a surface, or you’d imagine something slippery like ball bearings on a surface.

So, there’s something that’s caused the surface to become slippery. A person slips – that’s the hazard. Now the person may catch themselves; they may not fall over. They may suffer no injury at all. Or they might fall and suffer a slight injury; and, very occasionally, they might suffer a severe injury. It depends on many different factors. You can imagine if you slipped while going downstairs, you’re much more likely to be injured.

And younger, healthy, fit people are more likely to get over a fall without being injured, whereas if they’re very elderly and frail, a fall can quite often result in a broken bone. If an elderly person breaks a bone in a fall the chances of them dying within the next 12 months are quite high. They’re about one in three.

So, the level of risk is sensitive to a lot of different factors. To get an accurate picture, an accurate estimate of risk, we’re going to need to factor in all those things. But before we get to that, we’ve already said that hazard need not lead to harm. In this standard, we call it an incident, where a hazard has occurred; it could have progressed to an accident but didn’t, we call this an incident. A near miss.

We got away with it. We were lucky. Whatever you want to call it. We’ve had an incident but no he’s been hurt. Hopefully, that incident is being reported, which will help us to prevent an actual accident in future.  That’s another very useful concept that reminds us that not all hazards result in harm. Sometimes there will be no accident. There will be no harm simply because we were lucky, or because someone present took some action to prevent harm to themselves or others.

Mitigation Strategies (Controls)

But we would really like to deliberately design out or avoid Hazards if we can. What we need is a mitigation strategy, we need a measure or measures that, when we put them into practice, reduce that risk. Normally, we call these things controls. Again, now we’ve illustrated this; we’ve added to the funnels. We’ve added some mitigation strategies and they are the dark blue dashed lines.

And they are meant to represent Barriers that prevent the accident sequence progressing towards harm. And they have dashed lines because very few controls are perfect, you know everything’s got holes in it. And we might have several of them. But usually, no control will cover all possible causes; and very few controls will deal with all possible consequences.  That’s what those barriers are meant to illustrate.

That idea that picture will be very useful to us later. When we are thinking about how we’re going to estimate and evaluate risk overall and what risk reduction we have achieved. And how we talk about justifying what we’ve done is good. That’s a very powerful illustration. Well, let’s move on to safety requirements.

Safety Requirements

Now. I guess it’s no great surprise to say that requirements, once met, can contribute directly to the safety of the system. Maybe we’ve got a safety requirement that says all cars will be fitted with seatbelts. Let’s say we’ll be required to wear a seatbelt.  That makes the system safer.

Or the requirement might be saying we need to provide evidence of the safety of the system. And, the requirement might refer to a process that we’ve got to go through or a set kind of evidence that we’ve got to provide. Safety requirements can cover either or both of these.

The Essence of System Safety

Requirements. Covering. Safety of the system or demonstrating that the system is safe. Should give us assurance, which is adequate confidence or justified confidence. Supported with evidence by following a process. And we’ll talk more about process. We meet safety requirements. We get assurance that we’ve done the right thing. And this really brings us to the essence of what system safety is, we’ve got all these requirements – everything is a requirement really – including the requirement. To demonstrate risk reduction.

And those requirements may apply to the system itself, the product. Or they may provide, or they may apply to the process that generates the evidence or the evidence. Putting all those things together in an organized and orderly way really is the essence of system safety, this is where we are addressing safety in a systematic way, in an orderly way. In an organized way. (Those words will keep coming back). That’s the essence of system safety, as opposed to the day-to-day task of keeping a workplace safe.

Maybe by mopping up spills and providing handrails, so people don’t slip over. Things like that. We’re talking about a more sophisticated level of safety. Because we have a more complex problem a more challenging problem to deal with. That’s system safety. We will start on the process now, and we begin with hazard identification and analysis; first, we need to identify and list the hazards, the Hazards and the accidents associated with the system.

We’ve got a system, physical or not. What could go wrong? We need to think about all the possibilities. And then having identified some hazards we need to start doing some analysis, we follow a process. That helps us to delve into the detail of those hazards and accidents. And to define and understand the accident sequences that could result. In fact, in doing the analysis we will very often identify some more hazards that we hadn’t thought of before, it’s not a straight-through process it tends to be an iterative process.

Risk Reduction

And what ultimately what we’re trying to do is reduce risk, we want a systematic process, which is what we’re describing now. A systematic process of reducing risk. And at some point, we must estimate the risk that we’re left with. Before and after all these controls, these mitigations, are applied. That’s risk estimation.  Again, there’s that systematic word, we’re going to use all the available information to estimate the level of risk that we’ve got left. Recalling that risk is a combination of severity and likelihood.

Now as we get towards the end of the process, we need to evaluate risk against set criteria. And those criteria vary depending on which country you’re operating in or which industry we’re in: what regulations apply and what good practice is relevant. All those things can be a factor. Now, in this case, this is a U.K. standard, so we’ve got two tests for evaluating risk. It’s a systematic determination using all the available evidence. And it should be an objective evaluation as far as we can make it.

Risk Evaluation

We should use certain criteria on whether a risk can be accepted or not. And in the U.K. there are two tests for this. As we’ve said before, there is ALARP, the ‘As Low As is Reasonably Practicable’ test, which says: Have we put into practice all reasonably practicable controls? (To reduce risk, this is risk reduction target). And then there’s an absolute level of risk to consider as well. Because even if we’ve taken all practical measures, the risk remaining might still be so high as to be unacceptable to the law.

Now that test is specific to the U.K, so we don’t have to worry too much about it. The point is there are objective criteria, which we must test ourselves or measure ourselves against. An evaluation that will pop out the decision, as to whether a further risk reduction is necessary if the risk level is still too high. We might conclude that are still reasonably practicable measures that we could take. Then we’ve got to do it.

We have an objective decision-making process to say: have we done enough to reduce risk? And if not, we need to do some more until we get to the point where we can apply the test again and say yes, we’ve done enough. Right, that’s rather a long-winded way of explaining that. I apologize, but it is a key issue and it does trip up a lot of people.

Risk Acceptance

Now, once we’ve concluded that we’ve done enough to reduce risk and no further risk reduction is necessary, somebody should be in a position to accept that risk.  Again, it’s a systematic process, by which relevant stakeholders agree that risks may be accepted. In other words, somebody with the right authority has said yes, we’re going to go ahead with the system and put it into practice, implement it. The resulting risks to people are acceptable, providing we apply the controls.

And we accept that responsibility.  Those people who are signing off on those risks are exposing themselves and/or other people to risk. Usually, they are employees, but sometimes members of the public as well, or customers. If you’re going to put customers in an airliner you’re saying yes there is a level of risk to passengers, but that the regulator, or whoever, has deemed [the risk] to be acceptable. It’s a formal process to get those risks accepted and say yes, we can proceed. But again, that varies greatly between different countries, between different industries. Depending on what regulations and laws and practices apply. (We’ll talk about different applications in another section.)

Risk Management

Now putting all this together we call this risk management.  Again, that wonderful systematic word: a systematic application of policies, procedures and practices to these tasks. We have hazard identification, analysis, risk estimation, risk evaluation, risk reduction & risk acceptance. It’s helpful to demonstrate that we’ve got a process here, where we go through these things in order. Now, this is a simplified picture because it kind of implies that you just go through the process once.

With a complex system, you go through the process at least once. We may identify further hazards, when we get into Hazard Analysis and estimating risk. In the process of trying to do those things, even as late as applying controls and getting to risk acceptance. We may discover that we need to do additional work. We may try and apply controls and discover the controls that we thought were going to be effective are not effective.

Our evaluation of the level of risk and its acceptability is wrong because it was based on the premise that controls would be effective, and we’ve discovered that they’re not, so we must go back and redo some work. Maybe as we go through, we even discover Hazards that we hadn’t anticipated before. This can and does happen, it’s not necessarily a straight-through process. We can iterate through this process. Perhaps several times, while we are moving forward.

Safety Management

OK, Safety Management. We’ve gone to a higher level really than risk because we’re thinking about requirements as well as risk. We’re going to apply organization, we’re going to applying management principles to achieve safety with high confidence. For the first time we’ve introduced this idea of confidence in what we’re doing. Well, I say the first time, this is insurance isn’t it? Assurance, having justified confidence or appropriate confidence, because we’ve got the evidence. And that might be product evidence too we might have tested the product to show that it’s safe.

We might have analysed it. We might have said well we’ve shown that we follow the process that gives us confidence that our evidence is good. And we’ve done all the right things and identified all the risks.  That’s safety management. We need to put that in a safety management system, we’ve got a defined organization structure, we have defined processes, procedures and methods. That gives us direction and control of all the activities that we need to put together in a combination. To effectively meet safety requirements and safety policy.

And our safety tests, whatever they might be. More and more now we’re thinking about top-level organization and planning to achieve the outcomes we need. With a complex system, with a complex operating environment and a complex application.

Safety Planning

Now I’ll just mention planning. Okay, we need a safety management plan that defines the strategy: how we’re going to get there, how are we going to address safety. We need to document that safety management system for a specific project. Planning is very important for effective safety. Safety is very vulnerable to poor planning. If a project is badly planned or not planned at all, it becomes very difficult to Do safety effectively, because we are dependent on the process, on following a rigorous process to give us confidence that all results are correct.  If you’ve got a project that is a bit haphazard, that’s not going to help you achieve the objectives.

Planning is important. Now the bit of that safety plan that deals with timescales, milestones and other date-related information. We might refer to as a safety program. Now being a UK Definition, British English has two spellings of program. The double-m-e version of programme. Applies to that time-based progression, or milestone-based progression.

Whereas in the US and in Australia, for example, we don’t have those two words we just have the one word, ‘program’. Which Covers everything: computer programs, a programme of work that might have nothing to do with or might not be determined by timescales or milestones. Or one that is. But the point is that certain things may have to happen at certain points in time or before certain milestones. We may need to demonstrate safety before we are allowed to proceed to tests and trials or before we are allowed to put our system into service.

Demonstrating Safety

We’ve got to demonstrate that Safety has been achieved before we expose people to risk.  That’s very simple. Now, finally, we’re almost at the end. Now we need to provide a demonstration – maybe to a regulator, maybe to customers – that we have achieved safety.  This standard uses the concept of a safety case. The safety case is basically, imagine a portfolio full of evidence.  We’ve got a structured argument to put it all together. We’ve got a body of the evidence that supports the argument.

It provides a Compelling, Comprehensible (or understandable) and valid case that a system is safe. For a given application or use, in a given Operating environment.  Really, that definition of what a safety case is harks back to that meaning of safety.  We’ve got something that really hits the nail on the head. And we might put all of that together and summarise it in a safety case report. That summarises those arguments and evidence, and documents progress against the Safe program.

Remember I said our planning was important. We started off saying that we need to do this, that the other in order to achieve safety. Hopefully, in the end, in the safety report we’ll be able to state that we’ve done exactly that. We did do all those things. We did follow the process rigorously. We’ve got good results. We’ve got a robust safety argument. With evidence to support it. At the end, it’s all written up in a report.

Documenting Safety

Now that isn’t always going to be called a safety case report; it might be called a safety assessment report or a design justification report. There are lots of names for these things. But they all tend to do the same kind of thing, where they pull together the argument as to why the system is safe. The evidence to support the argument, document progress against a plan or some set of process requirements from a standard or a regulator or just good practice in an industry to say: Yes, we’ve done what we were expected to do.

The result is usually that’s what justifies [the system] getting past that milestone. Where the system is going into service and can be used. People can be exposed to those risks, but safely and under control.

Everyone’s a winner, as they say!

Copyright – Creative Commons Licence

Okay. I’ve used a lot of information from a UK government website. I’ve done that in accordance with the terms of its creative commons license, and you can see more about that here. We have we complied with that, as we are required to, and to say to you that the information we’ve supplied is under the terms of this license.

Safety Concepts Part 2: More Resources

And for more resources and for more lessons on system safety. And other safe topics. I invite you to visit the safety artisan.com website  Thanks very much for watching. I hope you found that useful.

We’ve covered a lot of information there, but hopefully in a structured way. We’ve repeated the key concepts and you can see that in that standard. The key concepts are consistently defined, and they reinforce each other. In order to get that systematic, disciplined approach to safety, that’s we need.

Anyway, that’s enough from me. I hope you enjoyed watching and found that useful. I look forward to talking to you again soon. Please send me some feedback about what you thought about this video and also what you would like to see covered in the future.

Thank you for visiting The Safety Artisan. I look forward to talking to you again soon. Goodbye.

Safety Concepts Part 1 defines the meaning of ‘Safe’, and it is free. Return to the Start Here Page.