What it does
A checklist carries hazards already learned, and good practice already established, into the next assessment. The assessor works the list against the site; each item gets a “compliant / not compliant / not applicable” answer with its reasoning recorded.
Its strengths
- Repeatable — different people ask the same questions, and results can be compared.
- Fast — needs no preparation and can be run on site.
- Carries learning — a lesson from an incident is added to the list and never forgotten again.
Its limit
A list will not find what is not on it. A new process, unfamiliar equipment or a scenario never experienced passes straight through a ready-made list. So the checklist runs alongside a question-generating method (what-if, HAZOP): the list guarantees coverage, the other provides depth.
Two things that break a list
- Length. A hundred-item list is ticked from habit rather than attention after item fifty. A short list specific to the task works better than a long, general one.
- Unreasoned compliance. A list that produces no findings means either the site is perfect or the list was not actually worked; the second is far more likely.
Maintaining the list
A checklist is a living document, fed by incidents, inspection findings and changes in legislation. A list unchanged for years is no longer auditing the plant but the knowledge its original author had on the day they wrote it.