Gaining Confidence in Goal-based Safety Cases

Goal-based safety standards are now a reality. As well as confidently satisfying the mandatory requirements laid down in these standards, there are a number of other secondary factors that influence the confidence a regulator or assessor has in any safety case produced. These factors include novelty of argument approach, experience of stakeholders and scale of the system and safety case. Currently, the certainty with which requirements are satisfied and the consideration of the other confidence factors often remains implicit within the certification process. In a goal-based safety case regime, users and regulators require intelligent customers who are aware of these issues and can explicitly consider them during the production of their safety case to increase the confidence of all stakeholders involved. Standards, guidance and other publications have covered in detail the structure and content of safety cases and this paper does not intend to repeat this information. Instead, this paper brings together and discusses the other confidence factors and approaches to managing them within the safety case development process.