Automatic Failure Analysis using Extended Safecharts
With rapid development in science and technology, we now see the ubiquitous use of different types of safety-critical systems in our daily lives such as in avionics, consumer electronics, and medical systems. In such systems, unintentional design faults might result in injury or even death to human beings. To avoid such mishaps, we need to verify safety-critical systems thoroughly and formal verification techniques such as model checking are a very promising approach. Currently, there is practically no automatic technique in formal verification that can aid system designers in formally modeling system faults and repairs. This work contributes by proposing an extension to the Safecharts model so that faults and repairs are easily modeled and then the Safecharts are transformed into semantically equivalent Extended Timed Automata models that can be directly model checked. The model checking results, such as witnesses of property specifications representing hazards, provide more concrete and useful information than the results from traditional failure analysis methods such as FTA. The proposed automatic failure analysis techniques are integrated into the SGM model checker, which can thus be used to verify safety-critical systems. Application examples show the feasibility and benefits of the proposed model-driven verification of safety-critical systems.