— Increasingly, licensing and safety regulatory bodies require the suppliers of software-intensive, safety-critical systems to provide an explicit software safety case – a structured set of arguments based on objective evidence to demonstrate that the software elements of a system are acceptably safe. Existing research on safety cases has mainly focused on how to build the arguments in a safety case based on available evidence; but little has been done to precisely characterize what this evidence should be. As a result, system suppliers are left with practically no guidance on what evidence to collect during software development. This has led to the suppliers having to recover the relevant evidence after the fact – an extremely costly and sometimes impractical task. Although standards such as the IEC 61508 – which is widely viewed as the best available generic standard for managing functional safety in software – provide some guidance for the collection of relevant safety and...