Author(s)

E.-j. Joung & K.-h. Shin

Abstract

Safety critical systems are those in which a failure can lead to serious and irreversible consequences. Nowadays digital technology has been rapidly applied to critical systems such as railways, aerospace, nuclear power plants, and vehicles. The main difference between an analog system and a digital system is that the software is the key component of the digital system. The digital system performs more varying and highly complex functions efficiently compared to the existing analog system because software can be flexibly designed and implemented. The flexible design makes it difficult to predict the software failures. This paper reviews safety standards and criteria for safety critical systems such as railway systems and introduces the framework for the software lifecycle. The licensing procedure for the railway software is also reviewed. Keywords: railway software standard, quality management procedure, product oriented view point, process oriented view point. 1 Introduction Railway systems put a great emphasis on safety more than any other component. It is true that software is increasingly used for functional realization of railway systems. Software has a certain congenital uncertainty to predict failures. The development of railway software has so far been inclined to function realization. In the case of using software without any safety certification, and if this use led to accidents, we will get severe and great damage. To deal with the situation, safety standards for railway software need to be suggested, and a verification and certification framework should be established to ensure that the software is developed with safety standards. We research other fields including nuclear power plants, aerospace, defenses in terms of quality management procedures, and review an appropriate safety management system for railway software.

Keywords

railway software standard, quality management procedure, product oriented view point, process oriented view point.