Blog Mil-Std-882E Safety Analysis

How to do Preliminary Hazard Analysis

In this 45-minute session, The Safety Artisan looks at how to do 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: How to do 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: How to do 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.

That’s it for the Demo…

End: How to do Preliminary Hazard Analysis

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

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