First article inspection (FAI)

When a new mold, die or process produces its first parts, every dimension, note and specification on the drawing is measured and documented, usually against a numbered ("ballooned") drawing with a results table. If anything is out of tolerance, the tool or process is corrected and a new first article inspected. Aerospace formalizes this in the AS9102 standard, and the automotive industry uses its own production part approval process (PPAP); other industries use simpler versions.

FAI catches tool errors before thousands of bad parts are made and creates a baseline record for later comparison.

Where it bites: skipping FAI on "simple" parts, or accepting a supplier's summary without the data. Repeat FAI after tool modifications, material changes or a move to a new factory.