Earlier work by the first author of this paper focused on predicting resilience in single-event disasters. Building on that earlier work, this paper considers the resilience of systems in the context of disasters involving multiple overlapping events. More specifically, the paper offers a means to measure the resilience of infrastructure systems subjected to more than one event over a timeline during which complete recovery from each single event may not have been achieved and may not even be achievable. Furthermore, the paper demonstrates how these resilience measures can be used to inform decision-making during the different phases of emergency management.

A key contribution of this paper is the development of a mathematical model to capture the partial resilience measure of each overlapping event, based on lost system functionality and recovery time. These are combined to produce a single resilience measure. The paper provides a basis for a quantitative analysis of multiple-event disasters, and uses an example to illustrate how this model can be applied to assess system resilience for a range of scenarios. A useful extension of this model would be to apply it to a practical example involving loss in a network of interconnected infrastructures, to establish total resilience and formulate strategies for mitigation, preparedness, response, and recovery for the cascading events considered. Related to such a practical application would be the determination of loss measures for interconnected infrastructures and how these could be treated to provide an overall measure of resilience.