Machinery and equipment

Machines made one at a time, where the design is not finished when the order is taken. A works quotes from a general arrangement and a conversation, then engineers the machine while it is already buying material against it, so two things decide whether the job makes money. The first is that a change has a price and the price is a matter of arithmetic, not opinion: moving a bearing housing is free while it is a drawing, costs the whole shaft once the shaft is on order, and costs that plus the hours to strip it out once it is in the machine. Every change here is priced part by part from where each part has actually got to, before anybody talks to the customer. The second is that most of a delivery time is not work. On a machine with a fourteen-week gearbox the shop is not the constraint, so a purchase is an activity in the plan exactly like a welding operation and the critical path usually runs straight through the purchasing department — which the plan draws, shaded, so nobody spends a month pushing the fitters harder for nothing.