Fail-safe testing of safety-critical systems: a case study and efficiency analysis

This paper proposes an approach for testing of safety-critical systems. It is based on a behavioral and a fault model. The two models are analyzed for compatibility, and necessary changes are identified to make them compatible. Then, transformation rules are used to transform the fault model into the same model type as the behavioral model. Integration rules define how to combine them. This approach results in an integrated model which then can be used to generate tests using a variety of testing criteria. The paper illustrates this general framework using a CEFSM for the behavioral model and a fault tree for the fault model. We apply the technique to an aerospace launch system. We also investigate the scalability of the approach and compare its efficiency with integrating a state chart and a fault tree.