1. A computer-implemented method, comprising: providing a tool for editing a workflow process model comprising: (i) a plurality of workflow process steps and (ii) branching logic comprising a precondition for traversing at least one workflow process step of the plurality of workflow process steps; receiving, by the tool, a request to assign a cost factor to the at least one workflow process step; and assigning the cost factor to the at least one workflow process step responsive to the request and by operation of one or more computer processors, such that a traversal of the at least one workflow process step by a first transaction invoking the workflow process model results in the cost factor being included in a total cost to be charged for executing the first transaction.