All cost models have the same high-level logic, which defines both the flow and effects of module evaluation (see
Cost Engine Details). The detailed logic of a cost model is specified by routing templates together with the CSL modules associated with the templates’ nodes, as well as by global CSL modules. The code in a CSL module specifies the rules and formulas that make up a particular portion of a cost model, such as the portion that computes a cost taxonomy for a particular process. This chapter describes how experienced users can employ CSL and routing templates in order to implement and customize the details of cost model logic.