• Taxonomy modules calculate those outputs, such as cycleTime and laborCost, that are specified by the module’s associated formula table in the CMWB.

• Selection modules establish values for special outputs associated with their module types, for example, machine for machine selection modules and tool for tool selection modules.

• Modules that return a boolean value, such as feasibility modules, consist primarily of rules. They generally return true if all the rules succeed; they return false if any rule fails.

• Process taxonomy: evaluated for each feasible process in the context of a particular stock selection, process routing, and machine selection. A routing’s process taxonomy modules are evaluated after costing of all the routing’s descendent operations. Process taxonomy modules calculate various physical quantities, durations, and monetary quantities in order to generate a complete cost taxonomy for the current part and process.

• Operation taxonomy: evaluated (if present) for each feasible operation in the context of a particular stock selection, process routing, machine selection, GCD, operation sequence, and tool selection. An operation’s taxonomy module is evaluated after costing of all the operation’s descendant operations. Operation taxonomy modules calculate various physical quantities, durations, and monetary quantities in order to generate a complete cost taxonomy for the current GCD and operation.

• Material stock selection: evaluated for each pruned, process-level routing. This module (if present for some process in the current routing) narrows down the candidate material stocks.

• Machine selection: evaluated (if present) for each feasible process in the context of a particular stock selection and process routing. This module selects a machine for the current process.

• Tool selection: evaluated (if present) for each operation in the context of a particular stock selection, process routing, machine selection, GCD, and operation sequence. This module selects a tool for the current operation.

• Process feasibility: evaluated (if present) for each process in the context of a particular stock selection and process routing. If the module returns true, the process is considered feasible, and the cost engine proceeds to machine selection; if the module returns false, the current process routing is abandoned (unless the process is optional, in which case it is removed from the current process routing).

• Operation feasibility: evaluated (if present) for each operation in the context of a particular stock selection, process routing, machine selection, GCD, and operation sequence. If the module returns true, the operation is considered feasible, and the cost engine proceeds to tool selection; if the module returns false, the current operation sequence is abandoned (unless the operation is optional, in which case it is removed from the current operation sequence).

• Template pruning: evaluated (if present) during the initial expansion of the process-level templates. If the module returns true, the current node is included in the current routing; if the module returns false, the node is removed from the current routing.

• Process optionality: evaluated (if present) for each process in the context of a particular stock selection and process routing. If the module returns true, the current process is included in the current routing; if the module returns false, the process is removed from the current routing.

• Operation optionality: evaluated (if present) for each operation in the context of a particular stock selection, process routing, machine selection, GCD, and operation sequence. If the module returns true, the current operation is included in the current sequence; if the module returns false, the operation is removed from the current sequence.