Integrating safety analysis and requirements engineering

Some systems failures are due to defects in manufacturing and design, however that there are a significant number of system failures which result from errors, omissions and inconsistencies in the system requirements. We thus need methods to support a ‘safe’ requirements engineering process whose objectives are to specify system requirements such that system states which compromise safety are avoided and to include, along with the requirements, a justification or safety case which explains why the specified system is indeed safe. This paper describes the extension of a viewpoint-based requirements method to incorporate safety analysis. requirements discovery as distinct from requirements analysis. This is particularly important for safetyrelated systems where the safety analysis is concerned with discovering what the system must not do rather than what services it should provide. We have addressed this problem by extending a viewpointoriented method for software requirements analysis so that it can cover broader systems issues and by incorporating support for safety analysis with this method. This method focuses on the processes of requirements discovery and analysis rather than the development of detailed system models.