Although the concept of resilience has been applied in a variety of settings (e.g., psychology,
psychiatry, ecology, social science, economy, and engineering) for several decades
(Renschler et al. 2010, Rose 2009), it has received an increasing amount of attention in the area
of risk management over the past several years. In the case of natural and man-made threats,
analyses of resilience have focused on critical infrastructures, communities, and regions and on
the resilience of various subsystems (e.g., a community’s or region’s economy, governmental
units, emergency services sector, the civilian population). As we discuss in Section 2.1, the
assessment of resilience varies according to the object of analysis. In addition, certain measures
of resilience, such as critical infrastructure resilience and economic resilience, are important both
in their own right and in their roles as determinants of resilience measured at a broader level,
such as community or regional resilience.
Ultimately, the goal of efforts to assess such properties as protection (vulnerability), resilience,
criticality, and so forth is to enable decision makers to make informed choices that will result in
cost-effective reductions in the risks associated with the range of natural and man-made threats
we face. Viewed from this perspective, we find that where we draw the line between such
indicators as vulnerability and resilience is less important than being able to develop a process
for measuring those indicators that will produce results that are consistent, reproducible, and
useful to decision makers. Having a clear and consistent process for distinguishing and
measuring resilience is a necessary element of a comprehensive approach to risk management.
The initial step in developing that process is to establish a working definition of resilience.