Definition of requirements for a safety critical communications system

This paper reports on a feasibility and formal design study carried out for a safety critical communications system. It highlights some important conclusions regarding the requirements definition process for safety critical systems and the role of formal methods within that process. The study applied novel formal approaches to system analysis and design in a practical application in order to gain an understanding of the technical and methodological issues surrounding their use. The paper concentrates on a few of the issues which were highlighted by the study. It starts by explaining the background to the development in terms of the expected role of formal methods within the requirements definition process, the target application and the anticipated nature of the system solutions. Next, issues arising in the various stages of the process are discussed and some of the problems encountered are highlighted. These impacted partly upon the conduct of the development and partly upon the technical solutions themselves. Finally, some of the conclusions from the study are discussed