Comeback

The definition is the shop's to make precise: within how many days, for the same complaint or any complaint, counting the parts failure that was not the technician's fault or not. Whatever the rule, the comeback has to be its own order linked to the original, with the customer's charge at zero, so it can be counted at all.

A comeback repaired on the shop's time adds hours to the clock and nothing to the flagged hours, which is why a shop's comeback rate shows up in its clock-hour effective labor rate before it shows up anywhere else. It also shows up in technician efficiency, where the hours went on the clock against no flag, and in a flat-rate pay plan, where the technician carried them.

What the customer is owed is the shop's own warranty. The FTC's consumer guide says plainly that "There is no 'standard warranty' on repairs" and that warranties "may be subject to limitations, including time, mileage, deductibles, businesses authorized to perform warranty work or special procedures". A shop's warranty terms, printed on the invoice, are what decides whether a return is a comeback or a new job; several provinces set a floor, and the rules pages have those words.

In Wrenchy the comeback is an order linked to the original at zero to the customer, with a vendor claim on the part where the part failed, so the count and the credit both exist.