Semantic Analysis and Consistency Checking of UML Sequence Diagrams

In a UML model, different aspects of a system are covered by different types of diagrams and this bears the risk that an overall system specification becomes inconsistent or incomplete. Hence, it is important to provide means to check the consistency and completeness of a UML model. This problem is addressed in this report by integrating the information specified in class and statechart diagrams into sequence diagrams. The information is represented as constraints attached to certain locations of the object lifelines in the sequence diagram and this allows the identification of gaps and contradictions in the specifications. Furthermore, dependencies between the sequence diagrams of a model can be investigated based on the previous results and represented in use case diagrams. The refined UML diagrams provide the foundation for the next iteration of the specification.