From Requirements Engineering to Safety Assurance: Refinement Approach

Formal modelling and verification are widely used in the development of safety-critical systems. They aim at providing a mathematically-grounded argument about system safety. In particular, this argument can facilitate construction of a safety case - a structured safety assurance document required for certification of safety-critical systems. However, currently there is no adequate support for using the artefacts created during formal modelling in safety case development. In this paper, we present an approach and the corresponding tool support that tackles this problem in the Event-B modelling framework. Our approach establishes a link between safety requirements, Event-B models and corresponding fragments of a safety case. The supporting automated tool ensures traceability between requirements, models and safety cases.