Answer: four documents and two records decide most of it.
- Incoming inspection records — is copper/compound checked, or just received?
- In-process test — is there a test between soldering and overmoulding, or only at the end?
- Final test records — kept per lot, with the actual values, not just "PASS"?
- Calibration — are the testers calibrated, and is the certificate current?
- Traceability — can a finished carton be traced back to a copper lot?
- Non-conforming lot — show one, and how it was closed.
A factory that can produce a closed non-conformance record is usually the one with a working system.