The cheapest place to find a wrong part is the goods-in bench. The most expensive place is your customer's plant.
Every defect has a cost that multiplies with each process step it survives. Caught at goods-in, a wrong component costs a return note. Caught at assembly, it costs a disassembly. Caught at end-of-line test, it costs a rework and a retest. Caught in the field, it costs a service visit and a conversation you did not want to have.
That arithmetic is why incoming inspection is not a bureaucratic ritual. Every delivery is checked against the drawing and the approved supplier list before it can be booked into stock, and material that does not match is quarantined rather than consumed. The rule is boring on purpose: suspect material never enters the flow.
The depth of inspection is risk-based, not uniform. A commodity terminal block from an approved distributor gets an identity and quantity check. A safety-relevant component, a first delivery from a new source, or anything with a documented history gets more: dimensional checks, certificate verification, sometimes a functional sample.
What makes the process work over years is the record. Lot identity is kept from goods-in through kitting into the build record, so a serial number can be traced back to the batch that went into it. Without that chain, a field problem becomes a guessing exercise across every unit ever built.
— GANI Manufacturing engineering team