Comeback
A vehicle returning for the same problem shortly after it was repaired. A direct measure of repair quality, and one of the few a shop can act on immediately.
A comeback is the same fault twice. It costs the labor of the first repair, the labor of the second, and the downtime of both, and it is the maintenance measure most directly within a shop’s own control.
Fleets that track it usually define a window, commonly thirty days or a set mileage, and count a repeat visit for the same system within it. The point of measuring is diagnostic rather than disciplinary. A cluster of comebacks on one component usually means a parts quality problem or a procedure gap rather than a technician problem, and treating it as a technician problem is the fastest way to stop hearing about them.
It is also the number most likely to be absent entirely. Nothing forces a shop to record that a visit is a repeat, so unless the work order asks, the pattern stays invisible while everyone in the shop already knows about it.