When Do We Use Gate Pass?

Hello Colleagues,
I work in a manufacturing company. Recently we have issues on when to issue gate pass. Some staff who resumes very early are not allowed out of the premises once they are in even when it is not past resumption time yet.
Do we need gate pass for staff who wishes to go out before the resumption time even when they are not taking anything out?

Gate Pass is the document that is needed when a person, has resumed for his duties and is going out for a brief period and coming back. This is done to verify the whereabouts of the employees at any particular time, so that if any untoward incident happens, then we have the knowledge.
So, if someone has entered the factory very early, then he/she will definitely punch their attendance, and if they are going out for any reason and it may be even before their assigned shift begins, then also, they need to take the gate pass, as otherwise, they are termed to be working, they may claim overtime for the same and also, if anything goes wrong, how can you prove, that he was not in the premises as there is nothing other than the CCTV camera that may have monitored him...
So, other than the schedule shift exit from the gate, the gate pass is necessary for all other exits.