Most factories can make a drawing once. Fewer can make it identically on the tenth PO, five years later, with the same person answering the phone. This article walks through the four operating disciplines that separate a reliable OEM supplier from a one-off vendor — and gives you the questions to ask on your next factory audit.
Drawing control
Every revision of every drawing lives on a controlled ERP with automatic version numbering. Shop-floor tablets pull the latest revision only — printed drawings are stamped with an expiry date. Ask to see the revision log for a part you have ordered before.
Material traceability
Every heat is stamped with a mill number that follows the material through cutting, machining, heat treatment and packing. A great supplier can pull the mill certificate for any serialised part in under 5 minutes.
Inspection discipline
- First-article inspection on every new revision.
- SPC on critical dimensions with control limits, not just spec limits.
- Calibrated gauges with visible calibration stickers on every workstation.
- Non-conformance reports that root-cause, not just re-work.
Export operating rhythm
The best suppliers have a dedicated export desk that handles documentation, customs and door-to-door logistics — you never chase a shipment through the factory's production planner. Ask how many countries they ship to weekly, and how many active INCOTERMs their team quotes fluently.
- Controlled drawings + material traceability are the non-negotiables.
- Inspection is a discipline, not a paper form — audit calibration and NCR closure.
- A dedicated export team beats a shared logistics coordinator every time.
- Ask about the fifth PO, not the first — repeat quality is what matters.