For the Bench Operation process, the cost model selects the feasible machine with the smallest length (specified by the machine property Usable Length).

A machine is considered feasible if it can accommodate the dimensions of the selected stock (with the stock oriented so that its width dimension is perpendicular to the ceiling). In particular, the machine is feasible if both the following hold:

See Material Stock Selection for Stretch Forming for information about stock length and width.

Note that 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.