DOE OSTI2012
There is strong agreement among policymakers, practitioners, and academic researchers that the concept of resilience must play a major role in assessing the extent to which various entities - critical infrastructure owners and operators, communities, regions, and the Nation - are prepared to respond to and recover from the full range of threats they face. Despite this agreement, consensus regarding important issues, such as how resilience should be defined, assessed, and measured, is lacking. The analysis presented here is part of a broader research effort to develop and implement assessments of resilience at the asset/facility and community/regional levels. The literature contains various definitions of resilience. Some studies have defined resilience as the ability of an entity to recover, or 'bounce back,' from the adverse effects of a natural or manmade threat. Such a definition assumes that actions taken prior to the occurrence of an adverse event - actions typically associated with resistance and anticipation - are not properly included as determinants of resilience. Other analyses, in contrast, include one or more of these actions in their definitions. To accommodate these different definitions, we recognize a subset of resistance- and anticipation-related actions that are taken based on the assumption that an adverse event is going to occur. Such actions are in the domain of resilience because they reduce both the immediate and longer-term adverse consequences that result from an adverse event. Recognizing resistance- and anticipation-related actions that take the adverse event as a given accommodates the set of resilience-related actions in a clear-cut manner. With these considerations in mind, resilience can be defined as: 'the ability of an entity - e.g., asset, organization, community, region - to anticipate, resist, absorb, respond to, adapt to, and recover from a disturbance.' Because critical infrastructure resilience is important both in its own right and because of its implications for community/regional resilience, it is especially important to develop a sound methodology for assessing resilience at the asset/facility level. This objective will be accomplished by collecting data on four broadly defined groups of resilience-enhancing measures: preparedness, mitigation measures, response capabilities, and recovery mechanisms. Table ES-1 illustrates how the six components that define resilience are connected to the actions that enhance the capacity of an entity to be resilient. The relationships illustrated in Table ES-1 provide the framework for developing a survey instrument that will be used to elicit the information required to assess resilience at the asset/facility level. The resilience of a community/region is a function of the resilience of its subsystems, including its critical infrastructures, economy, civil society, governance (including emergency services), and supply chains/dependencies. The number and complexity of these subsystems will make the measurement of resilience more challenging as we move from individual assets/facilities to the community/regional level (where critical infrastructure resilience is only one component). Specific challenges include uncertainty about relationships (e.g., the composition of specific supply chains), data gaps, and time and budget constraints that prevent collection of all of the information needed to construct a comprehensive assessment of the resilience of a specific community or region. These challenges can be addressed, at least partially, by adopting a 'systems approach' to the assessment of resilience. In a systems approach, the extent to which the analysis addresses the resilience of the individual subsystems can vary. Specifically, high-level systems analysis can be used to identify the most important lower-level systems. In turn, within the most important lower-level systems, site assessment data should be collected only on the most critical asset-level components about which the least is known. Implementation of the strategies outlined here to assess resilience will facilitate the following four objectives: (1) Develop a methodology and supporting products to assess resilience at the asset/facility level, (2) Develop a methodology and supporting products to assess resilience at the critical infrastructure sector level, (3) Provide resilience-related information to critical infrastructure owners/operators to facilitate risk-based resource decision making, and (4) Provide resilience-related information to State and local mission partners to support their risk-based resource decision making.
54 ENVIRONMENTAL SCIENCES↗