Damage-resistant CPS reliability modeling considering coupled system resistance effects

Cyber-physical systems (CPS) integrate computation components with physical components, connecting them to the internet and each other. Many CPS feature damage resistance properties, such as electrical vehicles and wind turbines. Current research often characterizes system resistance to the damage caused by shocks using a constant factor between 0 and 1, which may not fully reflect the system resistance. In this study, we propose a surprise function-based system resistance formulation to depict dynamic system resistance levels in responding to various shocks and discuss its statistical properties. We then extend our proposed resistance formulation and its properties to coupled system resistance scenarios that incorporate various nonfatal shocks and multi-phase system degradation phenomena. Based on these scenarios, we model system degradation in multiple phases, namely, stable, slow, and rapid degradation phases, and their corresponding reliability functions. Finally, we perform multiple numerical analyses to assess system reliability and compare the results with existing studies that consider resistance factors and functions. The main advantage of this study is that the proposed model offers a dynamic representation of system resistance by incorporating varying shock responses and multi-phase degradation phenomena, providing a new tool for reliability assessment when considering system resistance compared to traditional constant factor approaches.