Measuring Method Complexity: The Case of the Business Process Modeling Notation

Graphical models are used to depict various aspects of enterprise architectures. Process modeling methods in particular have evolved from simple flowcharts to newer methods that include a large number of diagramming symbols, which increases their perceived complexity. To date, two main approaches for the complexity evaluation of conceptual modeling techniques have been proposed: a set of metrics based on the meta-model of the technique, and an ontology-based approach based on a mapping of modeling constructs to a reference ontology. Existing related work in process modeling has concentrated on the ontological analysis of modeling methods. In this paper we complement the existing ontological analyses by developing a meta-model of the Business Process Modeling Notation (BPMN) and applying established meta-model based complexity metrics. Our research finds that – compared to modeling languages such as UML and the EPC – BPMN has very high levels of complexity. Furthermore, we see evidence that such complexity can be significantly reduced through the use of modeling conventions.