BPMN 2.0 Execution Semantics Formalized as Graph Rewrite Rules

This paper presents a formalization of a subset of the BPMN 2.0 execution semantics in terms of graph rewrite rules. The formalization is supported by graph rewrite tools and implemented in one of these tools, called GrGen. The benefit of formalizing the execution semantics by means of graph rewrite rules is that there is a strong relation between the execution semantics rules that are informally specified in the BPMN 2.0 standard and their formalization. This makes it easy to validate the formalization. Having a formalized and implemented execution semantics supports simulation, animation and execution of BPMN 2.0 models. In particular this paper explains how to use the formal execution semantics to verify workflow engines and service orchestration and choreography engines that use BPMN 2.0 for modeling the processes that they execute.