The RCE “rule” is that you must have a pre-alarm before a shutdown. The reason for this “rule” is that it is imperative to give operations a chance to make a correction before being shutdown. Anything less is not fair.
This “rule” is one that is born from experience. During a start-up working late into the night fighting the usual problems including a liquid dump valve that kept hanging open. Not wanting to troubleshoot why it was hanging open, one of the operators blocked it in and went on to other tasks they were chasing. The following day corporate big shots flew in on the company jet for a steak lunch to celebrate the start-up. As the steaks were about done the whole plant shutdown including the power generator. A high level shutdown had occurred on the vessel where the dump valve had been blocked in the night before and there was NO warning. That vessel had a high level shutdown but did NOT have any pre-alarm to warn the operator. Had it had a pre-alarm the operator could have gone over and unblocked the dump valve and saved the plant from a major shutdown. Needless to say the steaks were cold before everybody got around to eating. Lesson learned and “rule” developed.