Safety-Critical Systems, Formal Methods and Standards

Standards concerned with the development of safety-critical systems, and the software in such systems in particular, abound today as the software crisis increasingly affects the world of embedded computer-based systems. The use of formal methods is often advocated as a way of increasing confidence in such systems. This paper examines the industrial use of these techniques, the recommendations concerning formal methods in a number of current and draft standards, and comments on the applicability and problems of using formal methods for the development of safety-critical systems of an industrial scale. Some possible future directions are suggested. Further copies of the Technical Report may be obtained from the Librarian, Oxford University Computing Laboratory, Programming Research Group, Wolfson Building, Parks Road, Oxford OX1 3QD, England (Email: library@comlab.ox.ac.uk)