This is basically like a fire drill that is conducted in an office building environment. It is pointless if the participants know what's going to happen. The idea of these kinds of drills and inspections is that the people who end up participating in them not know what's happening so that we can assess how much training we need to have what kind of notice is what kind of announcements to control chaos. Planning them ahead and announcing them ahead is pointless. Everyone and I mean everyone should assume that I need to notice or alarm of an emergency be handled as an emergency whether it is a real emergency or a test.