Suggestion of the Certification Processes to Secure the Safety of Railway Software

摘要

The rapid growth of the digital technology has lead to the migration from analog system to digital system in the area of control system across the industries from the 1980s because of the increased capability and superior performance. In the railway industry, railway equipments also have begun to be designed and implemented based on digital technology with online and real time performance. Accordingly high speed and high density operation of train became possible. One of the significant differences between the digital system and the analog system is software. The software takes charge of the functions and the management of the digital system. The software is designed, coded and implemented into the system, and controls hardware components in order to satisfy the functional requirements of the system. The software can be flexibly designed and implemented, so it became very difficult to predict the software failures because of its increasing complexity. Therefore, it has become one of the key issues how to assure that the software is reliable, safe and secure. In this paper the safety criteria are suggested to secure the software safety for the field of railway system. The railway software has to be examined whether it is properly developed according to the safety criteria and certification processes. The certification processes are composed of acquisition, development and assessment process. Each process has documents related to the procedure, template, and technique. The certification processes are also suggested with more detail description in this paper.