A sign flickers, so somebody books a relamp. The lamp goes in, the flicker returns a fortnight later, and the second visit costs more than the first because nobody wrote down that the first one had not worked. Guest-facing faults are worse, because they arrive as complaints rather than as reports. “The door in 412 slams” is one sentence about a closer, a hinge and a reader, and which of the three it is depends on what was done to that door last.
Somebody types that the exterior sign is flickering and asks for a work order. The copilot flies to the sign on the front elevation and reads what is on it: the lamp was last replaced in March 2023 and is past its rated life, but the flicker pattern points at the driver rather than the lamp — so the work order goes to Northline Signs, who installed it, as WO-2026-0412. The same read works on door 412, where the closer, the hinge and the reader each carry their own history.
