A recent post about "HAZOP in hard times" has coincided with my discovery of the sunburst chart in Excel 2016 (I think these used to be called Opal Fruits) as a means to visualise potential causes for Loss of Containment.
Apart from the idea of a 'bikini' HAZOP (only covering the essential parts), the most notable comments relate to the effectiveness and efficiency of the team and, whilst developing this diagram, it struck me that a badly conducted study can be just as hit or miss (in terms of capturing the significant Deviations & Causes) as playing Darts or Wheel of Fortune.
My chart above is obviously a (non-exhaustive) simplification where all causes have equal contribution, whereas the actual evidence (based on HSL research) is typically as shown below.
The inner ring shows the Incident Cause which resulted in a Loss of Containment.
The outer ring shows the Risk Control Systems which failed thus allowing the deviation (incident Cause) to occur.
A significant number of losses are caused by Inadequate Isolation either from a Permit to Work failure or poor execution of Planned Maintenance Procedures. How many studies would have identified this or considered it credible ? Often discussions about the Maintenance deviation can focus on the the threat to the person carrying out the work and not the threat that this person is creating for others by their acts or omissions.
A few days ago, an AIChE webinar "When the Only Things Consistent About Your PHAs Are Inconsistencies" highlighted that different teams will view the same scenario in different ways and reminded us that...
OSHA believes that the process hazard analysis is best performed by a team with expertise in engineering and process operations, and that the team should include at least one employee who has experience with and knowledge of the process being evaluated. Also, one member of the team must be knowledgeable in the specific analysis methods being used.
Interesting that they use the term 'employee' and not 'contractor' or 'consultant' or simply just 'person' - but that's a separate discussion about theory vs practice.
Leading a HAZOP/PHA may look easy because it's a simple, systematic approach and apart from the challenge of 'herding cats' to ensure all stakeholders have an opportunity to contribute in an 'organised brainstorm'; not confirming the "known knowns" and then failing to expose the "unknown unknowns" is at least expensive (you've convened a meeting with costly participants and not achieved much) and at worst dangerous (you've missed a hazard or underestimated the risk) and to avoid this requires both technical and personal skills.
Good Leaders (and Scribes) are worth their weight in gold (or whatever currency you pay them in) - don't undervalue them or underestimate the time it takes to properly plan, execute and report a Hazard Study.