First article
The first piece produced by the real process, inspected in full to prove the routing, the tooling and the program before quantity runs.
The argument around a first article is always about who pays for it. The piece itself is cheap. The hours around it are not, a full inspection against every dimension on the print, the CMM program written and proven, the paperwork assembled, and the machine standing still while everyone finds out whether the process is what the estimate said it was. On a 500,000 piece program those hours vanish into the volume. On a 400 piece order they are a visible slice of the price, and a quote that ignores them subsidises the buyer’s risk reduction out of your margin.
On the floor the first article behaves as the moment of truth for the takeoff. Every feature the estimator missed, every setup the routing underestimated, every gauge nobody ordered surfaces here, at the most expensive possible time to learn it. Floors that treat the first article as a checkbox pay for it in expedited tooling and quiet concessions. Floors that treat it as the test of the estimate feed what they learn straight back into the next quote, which is the cheapest process improvement available.
It costs money when the amortisation is wrong. First article effort is a fixed cost, so the quantity it divides by decides whether it is pennies or dollars per piece, and an EAU that never arrives leaves the hours unrecovered. The denominator arithmetic, and why fixed costs deserve their own line rather than a hiding place inside the cycle, is walked through in how to quote a machined part. Where the customer requires the formal report, the paperwork has its own name and its own hours, covered under FAIR.