Safety Cases for Adaptive Systems of Systems: State of the Art and Current Challenges

Adaptive Systems of Systems (SoS) are able to react onto internal and external changes, adapting their member systems and reconfiguring the relations between these. Ensuring continued safety for adaptive SoS is challenging, because either the multitude of relevant configurations must be assessed at design time, or assessment must done dynamically at run time. The concepts of Modular Safety Cases (MSC) and Dynamic Safety Cases (DSC) might form part of a potential solution for these challenges. MSC provide the basis for coping with complexity in SoS and support structural adaption through their modularity. Yet, they are constructed at design time and do not well match with the dynamics and uncertainty of reconfiguration in adaptive SoS. DSC are adapted and re-evaluated at run time. A combination of both approaches could be the foundation for run-time safety assurance for adaptive SoS. In this paper, we analyse the state-of-the-art for MSC and DSC and briefly explain existing amendments to the original approaches. Further we identify current challenges for a full support of safe reconfiguration in adaptive SoS and define potential future research topics.