Why fingerprint attendance fails on real sites
Fingerprint readers are cheap and everywhere, and on an office floor of thirty people they mostly work. The failure shows up where the workforce is large, the hands are working hands, and everyone arrives inside the same ten minutes.
Worn and damaged fingerprints
Manual work wears down ridge detail. Masons, machinists, loaders and kitchen staff routinely fail fingerprint capture — and the person who fails is asked to try five times while a queue builds behind them.
One reader, one chokepoint
A reader handles one person every three to six seconds at best. Two hundred workers arriving at once is a queue measured in tens of minutes, every single shift.
It only sees one door
The reader records the gate it is bolted to. Side entrances, the loading bay and the canteen exit are all outside its world, which is exactly where mid-shift disappearances happen.