(71b) The Structured What If/Checklist – A New Twist On An Old Approach

The purpose of Process Hazards Analysis (PHA) is to identify and understand the hazards associated with the process being reviewed, to understand the potential resultant hazardous events, and to prevent those events by identifying all the potential routes to those events and ensuring that adequate safeguards are in place to mitigate their risk.  The application of a suitable hazards evaluation methodology (e.g., Hazard and Operability [HAZOP], Failure Mode and Effect Analysis [FMEA], What If, Checklist, et al) is a core process of the PHA.  All of the most-used methodologies are ultimately just different ways of asking “What If” questions.  The key to success is asking (and, of course, correctly answering) the “right” What If questions.  This paper will look at how a variation on an old theme can significantly improve the likelihood of asking all of the right questions, in a way that capitalizes on the strengths of some of the other approaches while avoiding their weaknesses, and is easier for PHA teams to apply initially and revalidate going forward.