Modelling languages play a central role in the development of complex and critical systems. One such language is the Unified Modeling Language (UML), a general-purpose modelling language widely used to describe software systems through, inter alia, class, state machine, and activity diagrams. For the development of high-quality systems, it is essential that systems engineers and simulation, verification, and execution tools share a common interpretation of the language semantics. Given the large number of modelling elements and concepts supported by such languages, it is important to clearly define the semantics and behaviour of individual elements and their possible combinations. The Precise Semantics of UML State Machines (PSSM) standard provides a precise definition of UML state machines, along with a test suite for verifying state machine tool implementations.

During this project, the student studies language semantics and existing modelling tools, and proposes new testing methods and supporting tools aimed at improving the correctness and consistency of modelling languages and tools. The project requires knowledge about modelling languages, language technologies, and verification techniques.