Challenges with Providing Reliability Assurance for Self-Adaptive Cyber-Physical Systems

Self-adaptive systems are evolving systems that can adjust their behaviour to accommodate dynamic requirements or to better serve the goal. These systems can vary in their architecture, operation, or adaptive strategies based on the application. Moreover, the evaluation can happen in different ways depending on system architecture and its requirements. Self-adaptive systems can be prone to situations like adaptation faults, inconsistencies in context or low performance on tasks due to their dynamism and complexity. That is why it is important to have reliability assurance of the system to monitor such situations which can compromise the system functionality. In this paper, we provide a brief background on different types of self-adaptive systems and various ways a system can evolve. We discuss the different mechanisms that have been applied in the last two decades for reliability evaluation of such systems and identify challenges and limitations as research opportunities related to the self-adaptive system's reliability evaluation.