Developing safety cases for integrated flight systems

The successful application of integrated systems into the safety critical domain requires careful management and a realistic approach to planning the introduction of such systems. One such approach is through work on technology demonstration programs. British Aerospace and the UK Ministry of Defence have embarked on such a project, considering the integration of several flight critical applications across a common architecture from various view points including a safety perspective. This presented two main challenges: First, how can we define the safety properties of an architecture which must support safety critical systems whilst providing a more flexible structure which increases availability and reduces physical weight and maintenance? Second, how do we structure and reason about the safety properties of this architecture in a way that can drive design and safety analysis? This paper describes how these two challenges were addressed as part of the technology demonstration project at British Aerospace.