Safety Case Maintenance: A Systematic Literature Review

abstract

Safety standards from different domains recommend the execution of a process for keeping the system safety case up to date, whenever the system undergoes a change, however, without providing any more specific guidelines on how to do this. Even if several (semi)automated safety case maintenance approaches have been proposed in the literature, currently, in the industry, the execution of this process is still manual, being error prone and expensive. To this end, we present in this paper the results of what is, to the best of our knowledge, the first Systematic Literature Review (SLR) conducted with the goal to provide a holistic overview of state-of-the-art safety case maintenance approaches. For each identified approach, we analyze its strengths and weaknesses. We observe that existing approaches are pessimistic, identifying a larger number of safety case elements as impacted by a change than the number of the actually impacted elements. Also, there is limited quantitative impact assessment. Further, existing approaches only address a few system change scenarios when providing guidelines for updating the safety case.