It depends entirely on the accuracy of the evacuation list and on that list being reachable from outside the building, usually on a phone. Sites that rely on a desktop export taken that morning tend to find the gap during a drill.
Common questions
What does Roll Call mean in simple terms?+
A roll call is the process of accounting for everyone who was in the building after an evacuation, carried out at the muster point. It answers one question: is anyone still inside.
How does Roll Call work in practice?+
It depends entirely on the accuracy of the evacuation list and on that list being reachable from outside the building, usually on a phone. Sites that rely on a desktop export taken that morning tend to find the gap during a drill.