A framework for the design of fault-tolerant systems-of-systems

Context: Systems-of-Systems (SoS) increasingly permeate everyday life in various critical domains. Due to their dynamic nature, guaranteeing their fault tolerance is challenging. Fault-tolerant SoS must deal with behavioral changes in constituent systems, whether accidental or deliberate. Goal: This work proposes ReViTA, a framework to assist professionals in designing fault-tolerant SoS that can continue to provide their function even in the presence of disturbances, i.e., events that affect the ability of an SoS to fulfill its mission. Methods: By adopting ReViTA, fault tolerance can be achieved by reconfiguring an SoS architecture to meet the critical mission requirements. Results: We performed two studies to evaluate the ReViTA acceptance by professionals. In the former, we gathered perceptions and suggestions from 14 professionals through individual interviews. In the latter, we involved a group of four professionals who applied ReViTA to a real-world scenario. Conclusion: The results demonstrate that ReViTA can effectively support professionals in designing faulttolerant SoS. Employing ReViTA also brings insights into costs and planning that are crucial for implementing fault-tolerance strategies. Using ReViTA facilitates a comprehensive understanding of conflicts and weaknesses in constituent systems and fosters collaboration between domain experts and decision-makers. Employing ReViTA also improves stakeholder communication and enhances resource utilization.