Safety Evidence Traceability: Problem Analysis and Model

[Context and motivation] Safety evidence plays an important role in gaining confidence in the safe operation of a system in a given context. For a large system, it is necessary to provide information about thousands of artefacts that might be used as evidence and about the relationships among themselves and also with other safety assurance assets. [Question/problem] Past research has only addressed some needs of traceability in safety-critical systems and thus has not provided a complete picture of safety evidence traceability. Lack of knowledge and awareness of these needs can result in poor evidence management and lead to certification risks. [Principal ideas/results] This paper aims to provide a broad overview of safety evidence traceability needs for practice and its associated challenges. We also propose a safety evidence traceability model, which has been validated with data from real-world critical systems. [Contribution] We discuss the motivation and challenges for safety evidence traceability, and present the various traces that need to be captured and maintained. This information can help researchers to shape future research based on industry needs and can help practitioners to gain a deeper understanding and a wider knowledge of safety evidence traceability, thereby facilitating safety assurance and certification.