The principal / class coordinator / professional teacher interested in calling a student's parent or any visitor to the school should enter their name in the system. The guard at the entrance, when the visitor arrives at the gate, enters the visitor's ID into the system and receives a confirmation / rejection of his entry.
The guard will not have to exercise his discretion in admitting guests
The school principal knew in real time which guests were at the school, who had already visited and who had left
The safety of the students and teachers will go up a notch. There is no need for unpleasant phone calls from invitees at the entrance to the school in front of the invitees (if the guard does not let them in for any reason)
Streamlining and implementing a new organizational culture