PNNL

Abstract

The concept of resilience is the subject of considerable discussion in academic, business, and governmental circles. The United States Department of Homeland Security for one has emphasised the need to consider resilience in safeguarding critical infrastructure and key resources. The concept of resilience is complex, multidimensional, and defined differently by different stakeholders. The authors contend that there is a benefit in moving from discussing resilience as an abstraction to defining resilience as a measurable characteristic of a system. This paper proposes defining resilience measures using elements of a traditional risk assessment framework to help clarify the concept of resilience and as a way to provide non-traditional risk information. The authors show various, diverse dimensions of resilience can be quantitatively defined in a common risk assessment framework based on the concept of loss of service. This allows the comparison of options for improving the resilience of infrastructure and presents a means to perform cost-benefit analysis. This paper discusses definitions and key aspects of resilience, presents equations for the risk of loss of infrastructure function that incorporate four key aspects of resilience that could prevent or mitigate that loss, describes proposed resilience factor definitions based on those risk impacts, and provides an example that illustrates how resilience factors would be calculated using a hypothetical scenario.