The evolution of resilience from its ecological roots to critical infrastructure applications: Concepts, definitions and future directions

Critical infrastructures (CI) in the water, energy, communication, transportation, and other sectors, are increasingly exposed to multifaceted hazards, ranging from extreme weather events to cyber‐physical attacks, as well as unprecedented environmental, socioeconomic, institutional and technological changes, that challenge the traditional “fail‐safe” design paradigm. This review article traces the evolution of the concept of resilience from its ecological and material science origins to its modern policy mandate in the planning, design, and operation of critical infrastructure systems against uncertainty. Various interpretations of resilience are examined and contextualized along other related, but different policy terms, like risk and sustainability, with which resilience is often conflated. Inherent traits or designed properties of systems that contribute towards resilience are also explored. The discussion highlights key challenges in operationalising resilience through quantifiable metrics while acknowledging the steps already taken to incorporate the concept into standards and policy. It is further argued that adopting a “stress-testing” approach to resilience quantification is an intuitive and powerful way to generate evidence-based resilience assessments. The need for cultivating a more “uncertainty-aware” design and management culture in the CI sectors is also discussed, and the critical role resilience has to play in such a culture is presented, as a direct, tangible response to the deep uncertainties that are emerging in the global physical, social and geopolitical landscape within which CIs are tasked to operate.