Integration of Safety Verification with Conformance Testing in Real-Time Reactive System

In the paper, we propose a method that can be applied to verify implementation in real-time reactive system. Different from other software model checking approaches, our method is based on testing. This approach allows the verification of safety property to be conducted directly on real code instead of models extracted from final implementation. Verifying that kind of models is a hard work and can only be applied to parts of the implementation. The method is done by establishing a connection between safety verification and conformance testing in real-time system. We first prove a theorem that in real-time system, under the input enabled precondition, if an implementation conforms to its specification and the specification satisfies the safety properties, the implementation satisfies it either. Then, based on contropositivity of the former conclusion, we present a test case generation framework which forms basis for generating test cases that can be used to detect violations of safety properties in the implementation. In addition, this test generation framework can also detect more nonconformance defects when compared with other real time test generation methods. The method is illustrated with a train gate control system.