This one's a bit specialised but hopefully someone can share their experiences: What do people do about reviewing a HAZOP if: Its an old HAZOP or The original study has been lost or is considered incomplete Do you do a full "re-HAZOP" or a shorter "review" version? Would appreciate anyones comments, Thanks, Coytanger.

I am not aware that a shortened or review version Hazard & Operability study exists?. In reply to your three questions: In the event of an old HAZOP:- An old hazop can be perfectly valid provided no significant changes have taken place (typically, any such changes would or should have been captured by Management of change or change control procedures). The original study has been lost:- No choice but to carry out a new study. Is considered incomplete:- Carry out a new study or if satisfied that areas that were considered not to be captured during the original study, subject the parameters applicable to the areas of concern to the appropriate guidewords.