These types of modules are normally evaluated in the context of a process routing (and possibly a material stock) and a particular routing node, but operation sequences have not yet been chosen, and no process has yet been costed.

For node’s that have a selectMachineAfterOpAssignment node attribute set to a non-null value, machine selection is delayed, and performed just before evaluation of the node’s taxonomy module.

Before performing machine selection for a node, the cost engine checks the node’s ancestors in the current routing to see if any has a machine selection module of its own. If one does, the ancestor machine applies to the current node, and the cost engine does not evaluate the current node’s machine selection module (if it has one).