Efficient Refinement Checking for Model-Based Mutation Testing

In model-based mutation testing, a test model is mutated for test case generation. The resulting test cases are able to detect whether the faults in the mutated models have been implemented in the system under test. For this purpose, a conformance check between the original and the mutated model is required. We have developed an approach for conformance checking of action systems, which are well-suited to specify reactive and non-deterministic systems. We rely on constraint solving techniques. Both, the conformance relation and the transition relation are encoded as constraint satisfaction problems. Earlier results showed the potential of our constraint-based approach to outperform explicit conformance checking techniques, which often face state space explosion. In this work, we go one step further and show optimisations that really boost our performance. In our experiments, we could reduce our runtimes by 80%.