Verifying Workflows with Cancellation Regions and OR-Joins: An Approach Based on Reset Nets and Reachability Analysis

When dealing with complex business processes (e.g., in the context of a workflow implementation or the configuration of some process-aware information system), it is important but sometimes difficult to determine whether a process contains any errors. Cancellation and OR-joins are important features that are common in many business processes. The presence of cancellation and OR-joins makes it difficult to perform verification. Therefore, existing approaches and tools are typically restricted to process models without such features. In this paper, we explore verification techniques for processes with cancellation and OR-joins. We present these techniques in the context of workflow language YAWL that provides direct support for these features. We have extended the graphical editor of YAWL with diagnostic features based in the results presented in this paper. The approach relies on reset nets and can easily be adapted to support other languages allowing for cancellations and OR-joins.