By default, for each AM process, aPriori selects the feasible machine with the lowest overhead rate, where overhead rate is the sum of the machine properties Direct Overhead Rate and Indirect Overhead Rate.

Machine feasibility constraints, for those processes that have them, are covered in the following sections:

aPriori selects only from preferred machines, if there is a feasible preferred machine of the appropriate type and the cost model variable usePreferredMachines is set to true (the default in starting point VPEs). If there is no feasible preferred machine of the appropriate type, 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.

You can manually select a machine using the Edit Machine Selection window, which lists the properties of all machines available at the facility.