Extracting the workflow critical path from the extended well-formed workflow schema

The critical path in a workflow schema is defined as the longest execution path from the start activity to the end activity. It can be utilized in many workflow issues such as workflow resource and time management. However, little work has been done on the critical path in a workflow because workflow control flows are much more complex than those represented with ordinary graphs and networks. In this paper, we first describe our workflow model with a set of workflow control constructs that provide sufficient power to express the models of most of today's business processes. Then, we propose a systematic method of identifying the critical path for a given workflow schema. Our proposed method is based on queuing theory because operational characteristics of the workflow schema can be modeled by a M/M/1 queuing network.