In brief
Check legal identity, contracting and payment consistency, model-level evidence, change control, inspection cooperation, packing clarity and the ability to explain limitations plainly.
Verify the counterparty
Match the quotation, contract, invoice and payment beneficiary. Resolve unexplained differences before payment.
Test the product evidence
Ask for current drawings, images, sample options and applicable documents for the exact model. Confirm dates and scope.
Review the operating process
Look for clear answers on approval, changes, inspection, packing, corrective action and shipment release rather than general quality slogans.