Formalizing structural semantics of UML 2.5 activity diagram in Z Notation

UML 2.5 Activity Diagram, being the latest version released in 2015, faces some serious problems inherent in UML itself. UML diagrams lack precise mathematical semantics which leads to ambiguities in its interpretation. Therefore, UML cannot be executed by model checkers for the presence of errors and inconsistencies. Z Notation is a widely used Formal Method, which offers robust notations for specifying static and dynamic aspects of any system and it also has a wide range of model checking tools. In this research, the informal semantics of UML 2.5 published by Object Management Group (OMG) has been transformed into Z notation. All the basic building blocks of Activity Diagrams and their structural semantics have been formalized using Z Schemas. Finally the developed formal semantics of Activity Diagram have been checked and analyzed using the Z/EVES toolset.