Meta Model Extensibility of BPMN: Current Limitations and Proposed Improvements.

The Business Process Model and Notation (BPMN) is the prevalent conceptual modeling language for business process modeling and process analysis. BPMN benefits from its expressiveness and the well-defined meta model, which is defined by the Meta Object Facility (MOF). The emergence of BPMN entails an increasing demand for language extensions in order to both benefit from the dissemination and apposite concepts. Although BPMN is one of very few languages that explicitly provides capabilities for its extension, the proposed mechanism reveals some shortcomings and inaccuracies concerning model abstractions, specificity and semantical clarity. A list of improvable aspects is hence provided based on an in-depth analysis of the extension mechanism. The analysis has a special focus on the abstract syntax (BPMN meta model). Several techniques for enhanced BPMN extension design are proclaimed by adapting alternative mechanisms for language extensibility: Profiling, under specification (hooking) and annotation (plugins and add-ons). The stated mechanisms are partly adapted from other modeling languages (profiling) or the field of Software Engineering (hooking, plug-ins, add-ons). Each approach is described by its core concepts, its application and by some examples. The approaches are finally compared regarding several criteria.