Routing

Two estimators can read the same print and produce 2 different routings, and from that moment they are pricing 2 different parts. Grind before heat treat or after it, drill on the lathe in the same chucking or on a second machine, wash once at the end or between every operation the cleanliness spec touches. Each choice moves cost, and none of them appears on the print, which is why the routing is where a floor’s actual experience earns its money.

The quoting argument underneath a routing is usually about a stop that did not need to exist. Every additional operation carries its own setup, its own queue time, its own handling and its own scrap opportunity, so a part that visits 5 work centers when 4 would do is overpriced in a way no single line reveals. The reverse failure is worse. A routing that skips a stop the part turns out to need, the straightening after heat treat, the second wash before plate, gets discovered on the floor after award and paid for out of margin.

Sequence matters as much as the list. The spool valve build in how to quote a machined part hones the bore after the outside diameter is ground, because the bore’s tenth-class tolerance would never survive being clamped for a later operation. A routing that ignores that kind of dependency prices a part the floor cannot actually make in that order, and the correction arrives as scrap.

When history is available, the strongest check on a proposed routing is the routing a similar part actually ran, changeovers, reworks and all, rather than the clean sequence someone wrote down before the job started.