Black-box Testing Tool of Railway Signalling System Software with a Focus on User Convenience

초록

Railway signalling system is the control equipment performing vital functions, and the validation on functional safety of its software is very important issue. Recently, various software testing tools are being applied to verify signalling system software. However, these tools are impossible to support black-box testing to verify the functional safety of embedded signalling system software, and a few black-box testing tools are currently commercialized. Since most of these commercialized black-box testing tools are depend on testing method through direct accessing to the target memory under testing, so there are a lot of difficulties in applying to the testing. In case of using by these existing tool, it is possible to test them only if internal memory address values which are occupied by the executing embedded software, and therefore they are rarely utilized to verify the embedded software at the actual operating environment. To overcome these problems, this study developed a black-box testing tool using communication interfaces which are utilized when operating actually. That is the real interface channel is used as an input and monitoring channel for black-box testing. This approach carries out the test in the manner where test data are input and the results are feedback with these interface channels by utilizing interface channels with other signalling equipment under operating. Boundary value analysis and equivalence class analysis modules were used to generate test cases within the developed new testing tool, and the pilot type of proposed testing tool has been completed, and the feasibility study is under progress now with one of railway signalling system software in Korea as its test target.