The Aspects of Business Processes: An Open and Formalism Independent Ontology

It is now well-established, that there are three important aspects of business processes: the behaviour aspect, the information aspect, and the organisation aspect. Dependent on the application area and the purpose of the models, there are even more aspects that need to be considered. Conceptually, most of the aspects of business processes are completely independent of each other. In fact, modelling these different aspects requires quite different formalism such as Petri nets, Entity-Relationship diagrams, or organisation charts. And, in principle, it should be easy to replace a modelling formalism for one aspect by another formalism for that aspect without effecting the models and formalisms used for the other aspects. In practise, however, formalisms for modelling business processes integrate all aspects, which spoils the conceptual independence of the different aspects, and, even worse, puts the focus on one aspect and neglecting others. In this paper, we present an ontology of business process modelling that captures this independence of the different aspects and that is independent of a particular modelling formalism. This way, this ontology captures the essence of the different aspects of business process modelling. This ontology is formalised by UML class diagrams showing the different concepts and their relations. Besides a nice graphical illustration of the ontology, the use of UML provides a technical basis for defining interfaces that must be met by concrete formalisms in order to implement a particular aspect. This way, the UML formalisation of the ontology is a first step towards a formalism independent workflow architecture. The focus of this paper, however, is on the concepts and the ontology, which is not biased towards a particular formalism and reflects the independence of the models for the different aspects.