Management of Change: When is a ‘change’ a ‘Change’?
The Center for Chemical Process Safety (CCPS) defines Management of Change as,
A temporary or permanent substitution, alteration, replacement (not in kind), modification by addition or deletion of critical process equipment, applicable codes, process controls, catalysts or chemicals, feedstocks, mechanical procedures, electrical procedures, safety procedures, emergency response equipment from the present configuration of the critical process equipment, procedures, or operating limits.
This definition is thorough but ― as with so many other elements of process safety ― it contains some circularity and ambiguity. For example, what is the meaning of the word critical in the phrase ‘critical process equipment’? (For that matter, what is the difference between process and non-process equipment?)
Unfortunately, it is not always obvious when a change is critical and when it is not. We face the following conundrum:
We use Management of Change (MOC) to evaluate critical changes.
How do we know if a change is critical?
We conduct an MOC to find out.
This critique of the word critical in this context is not just theoretical. It is more than mere word play. Examination of actual incidents shows that many of them were triggered by an apparently non-critical change. Indeed, it could be argued that changes which are judged prima facie to be critical actually require less analysis because they will certainly receive considerable attention and analysis. It may make more sense to focus on non-critical changes.
Small details matter in process safety. Unfortunately, accidents occur as small changes are done without consequences or are a near-miss event. More attention must be directed to non-critical changes as they can escalate into a major event.