Sometimes Less is More: Are Process Modeling Languages Overly Complex?

Modern business process modeling languages such as BPMN or EPC provide users with more constructs to represent real world situations than their predecessors such as IDEF or Petri Nets. But this apparent increase in expressiveness is accompanied by an increase in language complexity. In practice many organizations choose to only use a subset of the available modeling constructs. Using a well established ontology-based theory of representation, we analyze how this voluntary restriction affects the expressiveness and complexity of the resulting modeling vocabulary. We compare our empirical findings with two notation sets of the popular language BPMN - the core and full set. Our findings indicate that users are willing to accept ambiguity among modeling constructs and that the full element set of BPMN adds little expressiveness at the expense of considerably decreased ontological clarity. The findings are a first step towards an understanding of an optimal cost-effectiveness ratio for process modeling languages both in theory and practice.