The fingerprint machine at your gate has a failure rate. You already know the number, roughly, because you can see it in the queue every morning.
What's less obvious is whether the alternative is actually better, or just newer.
Why fingerprint readers fail at industrial gates
Capacitive fingerprint sensors need clean, undamaged, adequately moist skin. Factory and warehouse work produces the opposite: oil, dust, cement, cuts, callouses and skin worn smooth by repetition.
The result is a daily failure rate that nobody designed for. Each failure means a retry, and each retry lengthens a queue that two hundred people are standing in at shift change. The machine's throughput on paper and its throughput at 6am are different numbers.
There's also a design flaw nobody advertises: a PIN fallback. Almost every fingerprint installation has one, for the workers whose prints won't read — and a PIN can be handed to a colleague. Buddy punching doesn't survive because the system is weak; it survives because the system had to allow a workaround.
What face recognition does differently
Recognition at the gate identifies people while they walk. There's no device to touch, no queue to form, and nothing for the worker to remember or carry.
The buddy-punching problem largely resolves itself, not through enforcement but through the physics of it — a face is harder to lend than a card or a PIN.
And unknown people are logged rather than ignored. Contractors and visitors show up as unrecognised faces with a snapshot, which for most plants is the first time headcount on site has been a real number rather than an estimate.
The limits, which are real
We'd rather you hear these from us than discover them in month two.
Camera placement decides everything. A camera at face height, facing arrivals, works well. An overview camera mounted high in a corner does not, and no amount of resolution fixes the angle. Most sites need one dedicated gate camera even when everything else reuses existing hardware.
Angles and covering degrade it. A face more than about 60° off-axis, or heavily backlit, or covered by a mask or full helmet, will be detected as a person but may not be identified. In helmet-mandatory environments this matters a lot.
Enrolment quality matters, and drifts. A person enrolled from poor frames will miss occasionally. It's a ten-second fix, but somebody has to notice and do it.
It's a record, not a certification. If your payroll audit requires a certified timekeeping system, check that before retiring anything.
The consent question, which is not optional
Employees will ask what happens to their face. They're entitled to, and the answer needs to be ready before day one rather than improvised at the gate.
The honest answers, in our deployments: processing runs on a device at your site so no video leaves the premises; the face is stored as a mathematical template rather than as a photograph; and access is restricted to named administrators.
What that doesn't do is remove your obligation to inform staff and obtain consent. That's a policy step, it belongs to you, and we won't skip it on your behalf — a system introduced without telling people is a system that generates a dispute rather than an attendance record.
How we'd actually switch
Run both for a fortnight. Enrol during shift changes, keep the fingerprint machine live, and compare the two records daily.
At the end of two weeks you'll know your real match rate rather than a vendor's claimed one, and you'll have found the handful of people whose enrolment needs redoing. Then retire the machine — or don't, if the numbers didn't convince you.
That's a slower rollout than most vendors propose. It's also the one where nobody discovers a problem on the morning payroll depends on it.
Related reading: Attendance automation · Factory security · Why biometric attendance machines fail at the factory gate