Most failures in lockout/tagout procedures are not where reliability teams expect to find them. The dangerous moment is not the application of energy isolation. It's the return to service.

This is the half of the procedure that gets less attention in training, less rigour in execution, and almost no scrutiny in audits. The lockbox came off. The work was completed. The line was restarted. As far as most paperwork is concerned, the procedure worked. The trouble is that paperwork rarely captures what happened in the last few minutes.