Dynamic inoperability input-output modeling of a system of systems made of multi-state interdependent critical infrastructures

Critical Infrastructures (CIs) are fundamental for the operation of societies. They function interdependently in a system-of-systems configuration. Interdependencies are unveiled also when CIs become inoperable or only partially operable due to disruptions. The state of partial or full inoperability of a disrupted CI can cascade to the interdependent CIs connected to it in the system of systems, causing various degrees of inoperability. This paper presents a novel approach for modeling the disruption cascade dynamics in multi-state interdependent CIs. A Dynamic Inoperability Input-output Model (DIIM) is proposed to describe the multi-state transition dynamics of the CIs. A case study is worked out to show the application of the proposed approach to a system of systems formed by interdependent power and water networks.