You are responsible for customer support at ABC Corp. They recently set back a box of parts that they claim are all ‘bad.’ But on re-testing, they pass all in-house tests and are deemed ‘good.’ Now what do you do?

"In your scenario, we have already excluded the possibility that the parts themselves are bad, at least according to the way we measure 'bad' or 'good' in-house. Before I start chasing ghosts, I want to make sure that the customer is using the part correctly. Was there an undocumented change in the service environment such as a nearby leak or excessive temperature? Did they follow the wiring diagram? I would provide a few brand-new parts that we had verified were 'good,' and ask the customer if I could tag along and watch as they were installed and tested, so that I could make sure that we had captured all the requirements properly. If I could see something obvious during that phase of the problem-solving, I would bring it to their attention, and we would discuss whether the customer's written requirements needed to be updated, leading to a change in the part, or whether they could adapt to using the part as intended. If everything about the way they used the part was in order, I would want to document every detail of their real service environment and take it back to our product team for them to study. Is it possible that our in-house evaluations did not test the characteristic that was determining success or failure in the service environment? That's a possibility that has to be considered. These are the first few steps to how I would attack the problem you outlined."