The audit trail: what "verifiable presence" of a technician actually means
Three ways to confirm presence, three different levels of trust
When a company wants to know whether a technician was actually at a given site, it usually has three methods available: a signature on a paper sign-in sheet, a GPS check-in through a mobile app, or a scan of a tag physically mounted on the site. The difference between them isn't cosmetic. It's about what actually counts as proof.
A signature on a sign-in sheet proves only that someone held a pen at some point. It has nothing to do with physical presence at the equipment — a sheet can be signed in bulk at the end of the day, signed for a colleague, or filled in from memory with reconstructed entry and exit times. GPS is a step forward, but it has its own weakness: phone location can be faked with GPS-spoofing apps, signal accuracy inside reinforced-concrete buildings can be off by tens of meters, and even at its best GPS only confirms the phone was within some tens of meters of the site — not that someone stood next to a specific machine inside a hall.
What an NFC scan confirms, and what it doesn't
An NFC tag works through proximity communication — the phone has to be within a few centimeters of the chip for the read to succeed. That physical constraint is also the source of its reliability: you can't scan a tag remotely, you can't simulate it with an app, and the tag is mounted permanently to a specific piece of equipment or a fixed point in the building, so its location is known in advance and doesn't move.
What the system records isn't a technician's claim to have been somewhere. It's an event: a user account, a tag identifier, a timestamp. In Tracera, every RCP entry and every inspection is tied to a specific NFC tag — that data is stored with the record itself; it can't be reconstructed from memory or backdated without leaving a trace in the change history.
What it doesn't confirm is the quality of the work performed. A scan says "this phone was physically at this asset at this time," not "the work was done correctly." That distinction matters when designing procedures — proof of presence and proof of work quality are two different things, and no system replaces the second with the first.
An event log, not just an end result
A credible audit trail is more than a single "inspection completed" record. The system logs events as they happen — a fault reported, a fault closed, a report completed, an alert rule violated. That event log lets you reconstruct the sequence: who reported the fault, when it was assigned, when its status changed to resolved — instead of one summary status that hides what happened along the way.
For an HR or compliance team, that difference only surfaces during an audit or a labor dispute. A paper attendance sheet that could have been corrected with a pen doesn't hold up well against a record that points to the exact moment of a scan and the tag where the event occurred.
Where the tool's role ends
No system turns an NFC tag scan into proof beyond legal doubt — it's still company data, not an official document. Its value is that it's harder to fake and easier to reconstruct than paper or a plain GPS check-in, not that it removes the need for judgment when interpreting the records.
Before evaluating any presence-verification tool for audit purposes, ask the vendor one question: can the record it shows you be reversed or overwritten without a trace. The answer tells you more than any feature description will.