Subway Interlocking System Development Verification And Validation

The modern development of subway has become one of the important marks of the urban traffic modernization. The urban railway signal system is the key system which guarantees train operation safety, realizes operation command and train operation modernization and enhances transportation efficiency. Interlocking is the essential part of the subway signaling system.At present in the international, verification and validation technology is applied to guarantee the security and reliability of the safety related software. However, the quality assurance ability of safety related software is still weak in China, and the work in verification and validation field is almost blank.Firstly, based on the project of Subway Interlocking System Development, this paper establishes verification and validation methods by analyzing the European railway standards EN50128.Secondly, the static V&V techniques, including review, documentation inspection, code static analysis and code walkthroughs, are described in detail in this paper.Then the application of the white-box testing and black-box testing technology is described in this paper by introducing unit testing and software validation stage. The application of these methods includes designing of test cases, testing execution and testing results analysis.The verification and validation methods achieved considerable results in the practice of the Subway Interlocking System Development project. And it can direct the verification and validation work of the similar safety related software project.At last, the paper gives the further research direction. Testing automation, testing tools and testing simulation system need to be further researched in order to continuously improve the testing efficiency and software quality.