These types of modules are evaluated in the context of a process routing or operation sequence that includes the current node.

The cost engine has established a process-operation hierarchy that includes the nodes in the current routing or sequence and all their ancestors. The cost engine has not yet established the portion of the process-operation hierarchy below the nodes in the current routing or sequence. The cost engine might not have yet established the portion that includes operations to create a given sibling (in the GCD hierarchy) of the current GCD.

The cost engine has chosen a particular candidate material stock (if relevant). A machine or tool for the current node has not yet been chosen, and no nodes have yet been costed.