CMM
A coordinate measuring machine, the instrument that proves tight geometry, and a work center with a queue, a rate and a cost per piece like any other.
The mistake this term flags in a quoting argument is treating inspection as free. A CMM is a machine that was purchased, programmed and staffed, and a part that needs 4 minutes on it carries those 4 minutes in its cost exactly the way it carries seconds on a lathe. When a print’s GD&T turns sampling into 100 percent inspection, the CMM becomes a work center in the routing with its own cycle time, and sometimes it becomes the bottleneck, which means the quote’s promised volume is really a question about inspection capacity rather than machining capacity.
The quoting questions are concrete. Does the callout demand CMM proof or will a hard gauge do, because a gauge is a one-time cost that makes the per-piece check seconds instead of minutes, and the crossover between them is plain arithmetic against the program volume. Does the customer require recorded data per lot, which adds programming and reporting time, or just capability. And does the first article burden, the FAIR on aerospace work, need the CMM for days before production ever starts.
Where it costs money is the estimate that prices the cutting and assumes the checking. Inspection time on tight work gets paid by somebody, and when the rate and the routing both ignore it, it gets paid out of margin invisibly, one of the quiet omissions catalogued in what a burdened rate actually includes. The floors that quote inspection well treat the CMM like the hone or the grinder, a real resource with real seconds, priced from what similar parts actually consumed.