Criticality and Susceptibility Indexes for Resilience-Based Ranking and Prioritization of Components in Interdependent Infrastructure Networks

In infrastructure networks, each of the constituent infrastructure components (nodes and links) has its own significance. The extent to which each node is important to the network largely varies based on the resource or service it provides and the type of infrastructure nodes that are dependent on it. Similarly, the links are essential for the uninterrupted supply of resources to their respective destinations. To enhance the resilience of infrastructure networks, it is of vital importance to identify and quantify the consequences of infrastructure component failures on other components in the network, for which researchers have proposed several methods. Though all infrastructure nodes may be vulnerable to some kind of external hazards, resource and time constraints make it impossible for infrastructure managers and policymakers to adopt measures to enhance the resilience of every component in a network. Hence, it is necessary to address the issue of node and link prioritization to develop effective resilience strategies for networks. This study proposes two resilience indexes, a node criticality index and a node susceptibility index, to deal with two types of node ranking relevant to infrastructure network resilience. Then the node ranking indexes are used in a heuristic algorithm to rank and prioritize infrastructure links. The indexes can support decision-making for designing and managing resilience in interdependent infrastructure networks prior to a disaster, for identifying infrastructure components that warrant immediate restoration during or after a disaster, and for devising additional resilience strategies to handle heightened disaster risks during recovery.