The Pros and Cons of Including HAZOP Risk Ranking In Analyses
Written By Owen Llanwarne
As a team, we spend a lot of time delivering, reviewing and talking about HAZOPs. One thing that comes up time and time again in our group and within the wider process safety circles, is risk ranking in HAZOPs.
We are experienced risk assessors and HAZOP facilitators so our view is that risk ranking does add significant value to these studies through:
- Highlighting the highest risk items-it’s an obvious one but good to know.
- Allowing quick prioritisation of actions
- Steering the group to when actions should be raised. If the risk ranking is red, and no-one is calling out actions, then there’s a problem.
- Ensuring that the consequences of an event are fully described-it can be easy not to describe the harm if you don’t have to categorise it somehow, leading to a hazy HAZOP output.
Some may say it’s time wasting and against the core objective of a HAZOP; to reduce all risks to low levels irrespective of severity… but how do you measure this without actually plotting this on a risk matrix?
Others suggest meetings have become too focussed on the exact plotting of rankings on the risk matrix. We would agree, sometimes they do, but it is the facilitators job to lead the meeting and spot this, then quickly move the group on if there is no value being added to discussions.
We have seen recent examples where HAZOPs have had no risk ranking, and subsequently clients have thought their job was done at completion of HAZOP and LOPA. Without a HAZOP report flagging all the highest priority actions, clients are swamped in a world of “too many actions, too little time”.
It’s true, all actions should be closed, but it’s also true that the big hitters will reduce risks to the greatest extent.
The level of risk ranking can become a troublesome topic and can in some cases lead to what perceive as complete time wasting.
For example, some companies insist on three risk rankings in a study – pre safeguards, post safeguards and post action close out.
Our view is this – keep it simple, risk rank once – post safeguards, when you take credit for your design in the meeting.
If you’re really against deciding frequencies of events in a HAZOP, which can be another source of unnecessary debate, at least plot the severity of the event and force the team to fully describe the consequences.
So there we have it, touch paper lit. We welcome lively debate on this, everyone has an opinion – it what keeps our job interesting! Get in touch to chat!