BPMN 2.0 Execution Semantics Formalized as Graph Rewrite Rules: extended version

The Business Process Model and Notation (BPMN) standard version 2.0 informally defines a precise execution semantics. This paper defines that execution semantics formally, by defining the execution rules as graph rewrite rules. The paper shows that the formal definition of execution rules in this manner is intuitive and simple, in particular because they can be specified graphically, using the BPMN symbols, while maintaining mathematical rigour. Using graph rewriting tools, the resulting formal execution semantics can be used to directly execute models that are created in the BPMN. Therefore, it can be used as a reference implementation of the execution semantics and to test BPMN 2.0 engines, in combination with a set of BPMN test models that we also provide.