As I have stated already this week, I am a HAZOP kind of guy. I have used just about every methodology under the sun over the past 25+ years, and I have come to a personal conclusion that in almost every occasion, a HAZOP would have been the best methodology to utilize for a correct Process Hazard Analysis. My next favorite tool is to use a Failure-Modes-Effect-Analysis (FMEA) on specific pieces of equipment within a process, like say a compressor. Heck, I have even suggested to a couple of compressor manufacturers that a “competitive advantage” would be to have an FMEA done on your compressor and provide this analysis to customers who would be using the compressor in a process handling a highly hazardous chemical/extremely hazardous substance. Imagine the time savings across all customers and the marketing gold mine by being able to say our “compressor comes with a certified FMEA” (I know – I hate to use the word certified, but you know the marketing people will!!!)
But even when we choose a What-if or What-if Checklist as our methodology to conduct our PHA, there are some boundaries in which these tools NEVER INTEND to cover! One such “what-if” scenario that drives me CRAZY is to ask:
What if the Relief Valve has an incorrect setpoint?
An absolutely legitimate question to be asking in terms of process safety, but it is NOT a question I would ask in a PHA? This error would be covered in an array of other PHA activities…