Integrated techniques for software safety analysis

Existing techniques only address parts of the problem of assessing the safety of the software components of safety-critical systems. The main shortcomings of these existing techniques lie in their poor integration with each other and with the rest of the development process. The authors have identified three main areas where improved integration is necessary-semantic, procedural and operational integration. This paper describes what is meant by each of these terms, and describes work on the development of notations, methods and tools for safety analysis within the framework of the SSAP (Software Safety Assessment Procedures) project. The authors also address the broader context of safety analysis and describe links between SSAP and other relevant work. This paper first discusses the need and scope for integration, then examines the techniques which the authors have employed in SSAP. The authors discuss the current prototype SSAP system and conclude by exploring the broader context in which SSAP operates and the tools and methods with which it is intended to coexist