The machines for Mold Preparation, Hand Layup, and Bench Operation represent work areas of various sizes. For these processes, aPriori selects the lowest-overhead machine that can accommodate the length and width of the mold for the part: the mold length and width (see Tool Length, Width, and Area) must be no greater than the machine properties Usable Length and Usable Width.

Overhead, here, is the sum of the machine properties Direct Overhead Rate and Indirect Overhead Rate.

aPriori selects only from preferred machines, if there is a feasible preferred machine and the cost model variable usePreferredMachines is set to true (the default in starting point VPEs). If there is no feasible preferred machine, or if the cost model variable usePreferredMachines is set to false, aPriori selects from all machines. A machine is preferred if the machine property isPreferred (typically displayed as Is Preferred) is true.