Why one reader cannot cover a warehouse
A warehouse is not one door. It is an office entrance, two or three loading bays, a yard gate and often a separate driver entrance — each with different traffic and different people. Contact hardware forces you to choose which of them you pay to instrument.
The bays are where the workforce is
Pickers and loaders spend their day at the dock. A reader at reception measures the people least relevant to your operation.
3PL and casual crews churn weekly
By the time a temporary crew is enrolled on a machine, the contract has moved on.
Night shift has no supervision
The hours you most need an objective record are the hours nobody is watching the gate.