The NestFlow Interpretation of Workflow Control-Flow Patterns

Business process models are designed using a set of control-flow and data-flow constructs provided by the chosen Business Process Modeling Language (BPML). As research confirms, the adoption of a structured control-flow is always desirable for enhancing model comprehensibility and reducing the presence of errors. However, existing BPMLs cannot promote a fully structured approach to control-flow design because any restriction imposed on the existing language constructs results in a loss of expressiveness in terms of definable models. This paper proposes a novel BPML called NestFlow, characterized by a small set of language constructs that together overcome the aforementioned limitation. NestFlow expressiveness is discussed in terms of supported Workflow Control-Flow Patterns (WCPs), showing how the right combination of control-flow and data-flow constructs allows one to express most of these patterns in a structured way.