Machine Selection

For most processes in this process group, machine selection works as follows (exceptions include Electron Beam Welding and Laser Welding—see below):

• By default in starting point VPEs, the lowest-overhead virtual machine is selected.

• If the cost model variable preferVirtualMachines is false (it is true in starting point VPEs), the lowest-overhead default machine is selected, if there is one.

• Otherwise, the lowest-overhead machine is selected (regardless of whether it is a virtual machine). You can manually select a non-default machine.

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

For Electron Beam and Laser Welding, aPriori selects the feasible machine with the lowest per-part overhead rate.

Overhead rate is given by the sum of the machine properties Direct Overhead Rate and Indirect Overhead Rate. Per-part overhead rate is calculated by amortizing this value over the maximum number of parts that can fit in the machine (considering both lengthwise and widthwise orientations, with space between parts specified by the cost model variable EBWMinPartSpacing or LWMinPartSpacing--50mm in starting point VPEs) or over the number of parts specified by the user with the setup option Number of Parts in the Machine per Cycle.

An Electron Beam Welding machine is feasible if both the following hold:

• Machine can accommodate the weight and dimensions of the part (based on the machine properties Max Weight, Working Height, Working Width, and Working Length).

• Value of the machine property Is Load Lock Machine matches the value of the setup option Is the EB Welding Machine a Load Lock Machine (false, by default).

A Laser Welding machine is feasible if the machine can accommodate the weight and dimensions of the part (based on the machine properties Max Weight, Working Height, Working Width, and Working Length).

For Electron Beam and Laser Welding, aPriori selects only from virtual machines, if there is a feasible preferred machine and the cost model variable preferVirtualMachines is set to true (the default in starting point VPEs). If there is no feasible virtual machine, or if the cost model variable preferVirtualMachines is set to false, aPriori selects the default machine, if it is feasible. Otherwise, aPriori selects from all machines. A machine is virtual if the machine property isVirtualMachine (typically displayed as Is Virtual Machine) is true.