On the Development of Safety Requirements Based on Functional Analysis of LRT Stations in Concept Development Stage

Abstract For safety-critical systems including railways, there has been a growing need for effective and systematic safety management processes. The outcomes of efforts in this area are international safety standards, such as IEC 61508, 62278, and ISO 26262. One of the principal activities in the safety process is hazard analysis. For this reason,considerable efforts have been directed toward methods of hazard analysis. On the other hand, the hazard analysis methods reported thus far appear to be unclear in terms of their relationship with the system design process. In addition, in some cases, the methods appear to rely heavily on information regarding the hardware and software components, the number of which is increasing. These aspects can become troublesome when design changes are necessary. To improve the situation, in this paper, hazard analysis was carried out using the result of functional analysis early in the concept development stage for a safety-critical system design. Because hazard analysis is carriedout at the system level and the result is then used to develop the safety requirements, improvements can be expectedin terms of the development time and cost when design changes are required due to changes in the requirements.As a case study, the generation of safety requirements for the development of light rail transit stations is presented.