Treating every on-site check as an inspection hides an important distinction. A capable factory can still make a bad order, and a good-looking batch does not prove the supplier can repeat it reliably.
What a factory audit should answer
An audit or verification focuses on the supplier: legal identity, premises, equipment, staffing, production flow, quality systems, capacity and relevant product experience.
Use it before a meaningful commitment, especially when tooling, custom development, compliance or repeat volume make switching suppliers expensive.
Before supplier approval or another major commercial commitment.
What a product inspection should answer
An inspection focuses on the order. The inspector checks a defined sample or quantity against the approved product and inspection criteria, recording defects, measurements, functional results, packaging and evidence.
The report informs a buyer decision. It does not replace a clear specification, and it should not be treated as a guarantee that every unit is defect-free.
During production when correction still matters, or before shipment release.
When each control belongs
The right control depends on what is still uncertain. Supplier capability, materials, production progress and finished order quality require different evidence.
- Before supplier approval: supplier verification or factory audit.
- At production start: material or first-article confirmation for higher-risk products.
- During production: in-line inspection when early correction matters.
- Before shipment: final random inspection against the approved checklist.
Where AQL sampling fits
AQL is a statistical sampling approach often used for final random inspection. It defines how many units to inspect and the acceptance thresholds for critical, major and minor defects.
The sampling level and defect limits depend on the product, order and buyer's risk tolerance. Agree them before inspection—not after defects appear.