Towards Software Model Checking in the Context of Model–Driven Engineering

This work has been finished in March 2014.

The aim of this master thesis is to reduce the conceptual gap between software modeling and model checking. While model checking is successfully applied for hardware verification, it is not widespreadly used in model–driven engineering (MDE). Thus, we tried to reduce this gap by combining modeling and model checking concepts.

This thesis first describes the history and basic idea of both MDE and model checking with a focus on the technologies used in this thesis. Before presenting our new approach, existing solutions are compared. Most approaches propose to extend the Object Constraint Language (OCL) by temporal aspects. This allows to describe the behavior of a software system additionally to various properties of static models. However, one of the main missing features in general seems to be a user–friendly representation of the verification result helpful for debugging. Often, the technical spaces are changed.

With our solution we provide (i) a temporal OCL extension based on the Computational Tree Logic (CTL) and (ii) an OCL extension that introduces path selectors to extract interesting system configurations from the state space. Both OCL extensions were formally defined and implemented. We describe systems in terms of state spaces consisting of EMOF–model states and state transitions containing a mapping between model elements of different states. The system behavior is specified using an initial Ecore model and graph transformations based on the Henshin tool2. The approach, however, is designed to be flexible enough to allow an easy integration of any kind of behavior specification as long as a suitable state space can be derived thereof. Our model checking framework is developed with a focus on delivering not only the results, but also making the system behavior leading to the result comprehensible by providing a suitable tool including a web interface.

The implementation was evaluated in terms of performance to find out the maximum evaluable model size and query complexity. Further, a qualitative user study was conducted for evaluating the CTL extension and the tool. The results of this study indicate that both the CTL–based extension of OCL as well as the tool are a promising first step to integrate model checking in the MDE life cycle.

Abstract and paper may be found in our publication database.

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Robert Bill
Dipl.-Ing. Dr.techn.