Inspection

Inspection is the activity of checking a manufactured part against its specified requirements, dimensions, tolerances, finish, material, using measurement and other verification methods. It can happen at various points: first article inspection before full production, in-process inspection during a run, or final inspection before shipment.

Why inspection scope is itself a cost decision

The scope and rigor of inspection (sampling a few parts versus 100% inspection, a caliper versus a CMM) is itself a cost and time decision, driven by the part's criticality and the customer's requirements, not a fixed universal practice.

Where inspection requirements come from

Implied by tolerance and GD&T callouts, which determine what needs to be checked and to what precision, though a drawing or specification may also explicitly call out required inspection (such as first article inspection).

Common mistakes

Treating inspection as a fixed, one-size-fits-all step; the appropriate level of inspection varies by part criticality, customer requirement and process capability, not a single default.

Is inspection the same as metrology?

Metrology is the underlying science and practice of measurement; inspection is the activity of using measurement (and other methods) to check a part against requirements.

When does inspection happen?

It can happen at multiple points: first article inspection before a full run, in-process checks during production, and final inspection before shipment.

Does every part get 100% inspected?

Not necessarily; many processes use sampling inspection, with the appropriate level depending on part criticality and process capability.