1. In a computing environment comprising a workflow runtime, a method for optimizing workflow execution, the method comprising: at one or more processors of a computing system, identifying a workflow that includes a plurality of activities, along with a completion condition defining one or more states of execution of the plurality of activities that represent completion of the workflow; at one or more processors of the computing system, prior to initially executing the workflow, developing an optimized execution plan for executing the workflow to achieve the completion condition, comprising: identifying the plurality of activities of the workflow that could be executed to satisfy the completion condition, the plurality of activities including a first activity and a second activity that could be alternatively executed to satisfy the completion condition, at least in part; and ordering one or more activities from the plurality of activities into the execution plan and assigning system resources to the one or more activities based on an analysis of the plurality of activities and the completion condition, including ordering the first activity into the exclusion plan to the exclusion of the second activity based on the analysis preferring the first activity over the second activity for satisfying the completion condition; and at one or more processors of the computing system, subsequent to developing the optimized execution plan, executing the workflow according to the execution plan.