Improving Hazard Classification through the Reuse of Descriptive Arguments

Descriptive arguments are an intrinsic part of the process of determining the dependability of any system, particularly in the case of safety critical systems. For such systems, safety cases are constructed to demonstrate that a system meets dependability requirements. This process includes the application of hazard analysis techniques. However, such techniques are error-prone, time consuming and apply “ad hoc” reuse. Hence, the use of systematic, exhaustive hazard analysis can lead to an illusion of high confidence in the parent dependability argument that is compromised by lack of rigour. We have investigated the application of structure and reuse techniques to improve hazard classification arguments and their associated parent dependability arguments. A structure for hazard arguments has been presented and an example from a software hazard analysis has been exemplified using XML. Using two methods of structural reuse, hazard arguments can be improved for both argument generation and post argument construction analysis.