Transformation and Verification of Executable UML Models

In addition to static structures, the Unified Modelling Language (UML) supports the specification of dynamic properties of objects by means of statechart and sequence diagrams. Moreover, the upcoming UML 2.0 standard defines several kinds of actions to specify invocations, computations and the access of structural features. The formal specification technique compositional Temporal Logic of Actions (cTLA) provides for modular descriptions of behavior constraints and its process composition operation corresponds to superposition. Furthermore, cTLA facilitates the selection of an arbitrary subsystem of a complex specification which is composed of processes. We introduce an approach for formal-based refinement verifications of detailed UML models which fulfill more abstract ones. In a first step of the verification, the abstract and the detailed model are transformed to cTLA specifications. Thereafter, we can prove that the cTLA specification of the more detailed model implies the cTLA description of the more abstract one by application of the model checker TLC (Temporal Logic Checker).