The role of safety cases in risk management

There are similarities in the approaches to managing security and safety risks and it has been suggested that the safety case approach used in National Air Traffic Services (NATS) may be of interest to the security fraternity in the approach to managing security risks. Although the paper describes the use of safety cases in NATS for air traffic control systems the reader may assess the relevance of the approach for security by substituting the word "security" for "safety" and the word "threat" for "hazard" in reading this paper. Effective safety management requires the risks associated with a system, function or operation to be identified, controlled and mitigated as far as reasonably practical. A safety case is a formal document which presents the evidence, arguments and assumptions that this is so, and thus makes the risk management process visible to both users and the regulator (Civil Aviation Authority). This paper describes how safety cases are developed and used in the safety management and regulation of the UK Air Traffic Service.