Procedures to Apply Safety Criteria for the Safety Critical Railway Software

초록

In the railway industry, railway equipments 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. The safety criteria were suggested to secure the software safety for the field of railway system by KRRI (Korea Railroad Research Institute) project funded by MLTM (Ministry of Land, Transport and Maritime Affairs) in Korea. Railway software has to be examined whether it is properly developed according to the safety criteria. The safety criteria are just described in a brief description, so it is difficult to understand and also difficult to apply to the railway software development project. For this reason, we also suggest railway software development methodology and certification processes. The development methodology has seven steps and composed of procedure, template, and technique documents. The certification processes are composed of acquisition, development and assessment process. The certification processes also have documents related to the procedure, template, and technique. In this paper, detail description for the development methodology and certification processes is described to easily apply the railway software safety criteria to the railway software development project.