Analysis of the Safety Properties of a System from the Viewpoint of the Interactions of its Components

In safety-critical systems, software safety analysis aims to provide confidence that the risk associated with the software is acceptable. Accidents in safety-critical systems are usually associated with the occurrence of multiple failures in the system components, or with the lack of adequate error containment mechanisms. The process of safety analysis can be enhanced if the appropriate abstractions are provided for the modelling and analysis of the system components and their interactions. This paper shows how a co-operative object-oriented approach can be used in the analysis of the safety properties of a system by focusing on the interactions between its components. The feasibility of the approach is demonstrated in terms of a case study which deals with the safety procedures associated with the launching and flight of a sounding rocket.