On Defining the Behavior of OR-joins in Business Process Models

The recent literature on business process modeling notations contains numerous contributions to the so-called OR-join (or inclusive merge gateway) problem. We analyze the problem and present an approach to solve it without compromising any of the two major concerns that are involved: a) a clear semantical definition (design), which also clarifies what has to be implemented to achieve the intended generality of the construct, and b) a comprehensive set of static and dynamic analysis methods (verification of properties of business process models using the construct). We provide a conceptually simple scheme for dynamic OR-join synchronization policies, which can be implemented with low run-time overhead and allows the practitioner to effectively link the design of business process models with OR-joins to an analysis of the intended model properties. The definitions have been experimentally validated by a graph-based simulator.