On Role Resolution Decisions in Workflow Systems

Workflow systems provide a key technology to enable business process automation. One important function of workflow management is role resolution. Workflow role resolution is the mechanism of assigning tasks to individual workers at runtime according to the role qualification defined in the workflow model. Role resolution decisions directly affect the productivity of workers in an organization and it is important to study policies governing these decisions. In this paper, we model role resolution decisions in workflow systems and identify certain characteristics of workflow role resolution leading to interesting modeling and computational challenges. We propose several optimization-based policies that utilize online batching and compare their performance with several policies used in the current workflow practice. In our computational study, we examine three workflow system performance measures including maximum flowtime, average workload, and workload variation under these policies in different workflow business scenarios. These scenarios vary by overall system load, task processing time distribution, and the number of workers, representing different types of operating environments. Based on the computational results, we obtain the following managerial insights: (a) As the overall system load increases, the benefit of using batchingbased online optimization policies becomes more significant. (b) Processing time variation has a major impact on system performance, and higher variation favors optimization-based policies. (c) Average workload and workload variation can benefit from online optimization.