Transformation of UML Activity Diagram for Enhanced Reasoning

Abstract

IT industry has adopted unified modeling language activity diagram (UML-AD) as a de facto standard. UML AD facilitates modelers to graphically represent and document business processes to show the flow of activities and behavior of a system. However, UML AD has many drawbacks such as lack of formal semantics i.e. ontology used for the constructs based on intuition that vaguely describes processes and no provision for verifiability. Petri Net (PN) has been around for decades and used to model the workflow systems but PNs and its variants are too complex for business process modelers with no prior experience. A logical foundation is desirable to construct a business process with a precision that facilitates in transforming UML AD into a formal mechanism supported by verifiability capabilities for enhanced reasoning. Therefore, in this paper, we will provide a framework that will provide formal definitions for UML AD core terms and constructs used for modeling, and subsequently transform them to formal representation called point graph (PG). This will provide an insight into UML AD and will improve the overall functionality required from a modeling tool. A case study is conducted at King’s College Hospital trust to improve their patient flows of an accident and emergency (A&E) department.