Safety case patterns-reusing successful arguments

Common argument approaches exist between safety case developments. Informal reuse of safety case material already occurs-but in an uncontrolled, unpredictable and potentially dangerous manner. Based on the principles of design patterns combined with the safety argument representation concepts provided by the Goal Structuring Notation, we have developed the concept of safety case patterns. Using these patterns, it has been possible to identify and record reusable arguments in a number of situations and at different levels within the safety case. By creating a 'recipe book' of these approaches (our ongoing activity), we believe it is possible to capture expertise and improve safety case construction.