Center for Infrastructure Protection & Homeland Security

A Socio-Technical Approach to Critical Infrastructure Resilience

Susan Spierre Clark and Thomas P. Seager
School of Sustainable Engineering and the Built Environment, Arizona State University

Whereas risk assessment is useful for mitigating and planning for events that we expect to occur, resilience is required to deal with low probability and often high consequence events that can be unpredictable due to the complex nature of our social, ecological, and technological systems.  The increasing frequency, scale, and damages associated with recent events has called for a shift in focus from minimizing losses through risk analysis to improving threat preparation, planning, absorption, recovery, and adaptation through resilience.

Evidence of this shift includes the 2013 U.S. Presidential Policy Directive (PPD-21) on Critical Infrastructure Security and Resilience that ‘advances a national unity of effort to strengthen and maintain secure, functioning, and resilient critical infrastructure.’[1] Also in 2013, the American Society of Civil Engineering (ASCE) released a Report Card for America’s Infrastructure, which revealed the poor condition and performance of the nation’s infrastructure (earning a grade of D+) based on the capacity, condition, funding, future need, operation and maintenance, public safety, and resilience of infrastructure categories.[2] ASCE also estimated that the investment needed by 2020 to maintain U.S. infrastructure in good condition (or earn a grade of B) is $3.6 trillion, which creates a funding shortfall of $1.6 trillion based on current funding levels.[3] The poor condition of U.S. infrastructure has real impacts on public health and safety. For example, motor vehicle crashes in which roadway condition is a contributing factor cost the U.S. economy more than $217 billion each year.[4] Therefore, a natural or man-made disaster is not necessary for critical infrastructure to fail nor to create devastating losses.

The state of U.S. infrastructure and the lack of adequate funding, not to mention the threat of natural or manmade disasters, means that failures are inevitable. My colleagues and I at Arizona State are operating on this assumption and studying how critical infrastructure systems (i.e., water, energy, roads, and food systems) may fail safely as well as how we can adapt and learn from these inescapable failures. This resilience paradigm embraces safe-fail implementation across the life cycle of critical systems while maintaining or enhancing ecosystem services, improving social well-being, and exploiting new technologies. The first year and a half of our research on resilience (including several federally funded resilience projects) has revealed four particular barriers to building resilient infrastructure systems:

1. Lack of understanding of what constitutes resilience:

The concept of resilience now plays a critical role in advancing understanding of fields as diverse as ecology, child psychology, business management, cyber security, and infrastructure. Unsurprisingly, resilience concepts have been applied in different disciplines without reference across disciplinary boundaries, limiting transfer of knowledge from one discipline to others. Partly as a consequence, infrastructure managers lack generalizable resilience metrics, measures and mathematical models applicable for a diverse set of applications and contexts.[5] Particularly problematic is the intellectual disaggregation of resilience understandings in the social sciences from those in the engineering.

2. Interdependence of complex infrastructure systems obscures understanding of those systems:

There is a paucity of information on how infrastructure systems may be vulnerable to failures in other infrastructure systems on which they depend. For example, an electricity grid that relies heavily on thermoelectric generation, which requires water for cooling, is vulnerable to water supply shortages and/or water temperature increases from climate change.[6]  In return, water supply systems depend on electricity for pumping and conveyance, and is vulnerable to electricity generation disruptions. Thus, improving societal resilience requires understanding and mitigating not only the risks to individual infrastructure systems, but also mitigating how failures in one system can lead to disruptions in others.[7]

3. Resilience require socio-technical knowledge integration:

Vulnerability in critical infrastructure systems is not isolated to physical infrastructure but can be the result of the institutions, decision makers, and policies that govern them. Yet there is a lack of knowledge about how governance structures themselves introduce vulnerability and can be transitioned towards resilient configurations. In general, lifeline infrastructures tend to be regional systems, yet governing institutions follow state and local jurisdictions instead of around infrastructure services.[8] In our study of water and energy systems in the Southwest,[9] we have discovered institutional disaggregation and fragmentation despite the tightly coupled physical infrastructures. In addition, each domain seems to have distinct priority sets that can compete with the priorities of interdependent systems. Thus, improving the resilience of the coupled systems will require a coordinated effort that considers both infrastructure and institutions, which requires new approaches of institutional analysis.[10]

4. Incentive and governance structures present obstacles, even where understanding is sufficient:

Finally, even if we did have a generalized understanding of resilience, knew the vulnerabilities of complex, interdependent systems, and had tools for evaluating institutional resilience, we would still not have the governance structures necessary to incentivize the investment in resilience constructs beyond security and reliability, which either resists change or accept changes at the margin.[11] That is, it is less expensive in the short-term for our institutions to incrementally fix failures than try to anticipate and pro-actively replace infrastructure before it fails. Yet resilience requires acceptance of, and investments in, the capacity of our socio-technical infrastructure to anticipate and adapt or evolve as our needs, values, and technologies change over time. If we don’t have the willingness to invest in maintaining our current critical infrastructure systems, we certainly have work to do in making the case for investing in the adaptation or transformation of infrastructure systems.

With these challenges in mind we have constructed an interdisciplinary, socio-technical research team at Arizona State, as well as with collaborating institutions, to try and overcome some of these barriers. While we don’t claim to have all the answers, my colleagues and I would like to share some of the unique ways that we are approaching the resilience of socio-technical critical infrastructure systems.

SAAL Resilience Processes

Examination of the literature in multiple fields reveals that the concept of interdependence is a consistent theme present in almost all disciplines and certain processes are understood to be essential to resilience of all human systems: sensing, anticipating, adapting, and learning (SAAL). Therefore, we argue that a fundamental understanding of resilience that permeates disciples requires that we think of resilience as a process or something that is performed not possessed. This means that resilience cannot be measured at the systems scale from the examination of component parts, but the outcome of the SAAL recursive properties that is distinct from, but complimentary to, risk analysis.[12]

Institutional Resilience and Knowledge System Analysis

The use of the SAAL resilience processes for studying system resilience has been useful for the integration of institutional landscapes and knowledge systems with physical infrastructure models. We define institutions as the formal and informal rules, organizations, and norms that govern socio-technical systems. A process of investigation has already been initiated on how the key governing institutions of critical systems sense, anticipate, adapt, and learn from past failures.[13] Furthermore, we think of knowledge systems as the socio-technical systems used by institutions to organize the generation, evaluation, circulation, and application of knowledge to decision-making.[14] We hypothesize that the SAAL resilience processes are in fact knowledge systems, where each process involves the generation, evaluation, circulation, and application of knowledge.[15] Thus, SAAL has become our foundation or common reference for socio-technical integration.

Resilience Games and Simulation

Another strategy for fusing technical and social perspectives is through gameplay and simulation exercises. We are developing a learning game to conduct scenario planning workshops with key stakeholders, experts, and practitioners working in critical infrastructure sectors in the Southwest. The goal of this initiative is to pilot strategies for adaptive and anticipatory governance that link scientific insights to reductions in long-term infrastructural vulnerability. Similarly, we are constructing a computer-based Resilient Infrastructure Simulation Environment (RISE) that allows participants to experiment and adapt in response to simulated stress scenarios.[16] Our goal is to observe how individuals and groups respond to scenarios and through repeated participation, we want to train them to respond better. The principal hypothesis motivating this strategy is that resilience requires new patterns of improvisational and adaptive thinking in design and operation of infrastructure systems that can be enhanced through practice with ‘surprise’ experiences in a simulated complex network environment.

Positive Case Studies of Resilience

We observed that resilience engineering research predominantly focuses on the study of how systems are vulnerable and how they fail. Less studied are the positive cases of disasters that were averted by adaptive response. To address this, we are pioneering a study of positive cases of adaptive infrastructure systems that avoided catastrophe so that we can learn from their success. Using qualitative interviews and quantitative data analysis, our approach will describe the characteristic resilience processes, including sensing, anticipating, adapting, and learning that resulted in mitigation of disastrous consequences in high stress contexts.[17]

Through these and other techniques, we recognize the need for an overall change in mentality to address the identified resilience barriers. This change in mentality requires a different set of skills than those we have been rewarding, and therefore requires a new approach to training and education. At Arizona State we are developing resilience engineering curriculum that emphasizes a shift from fail-safe to safe-fail objectives, from employing techniques of reduction to admitting and addressing incompleteness, from our obsession over definition to being comfortable with ambiguity, from specification of probabilistic hazards and risks to the notion of surprise and emergence, from the focus on reliability to the recovery of systems, as well as from the current centralized structure of infrastructure to the design of distributed critical systems. We are excited to adapt and learn as our research and education initiatives continue.

Author Biographies:

Dr. Susan Spierre Clark is a Research Assistant Professor in the School of Sustainable Engineering and the Built Environment at Arizona State University.

Dr. Thomas P. Seager is an Associate Professor in the School of Sustainable Engineering and the Built Environment at Arizona State University.


[1] White House, Presidential Policy Directive/PPD-21—Critical Infrastructure Security and Resilience, (Feb. 12, 2013), available at https://www.whitehouse.gov/the-press-office/2013/02/12/presidential-policy-directive-critical-infrastructure-security-and-resil.

[2]“Report Card for America’s Infrastructure,” American Society for Civil Engineers (2013), available at http://www.infrastructurereportcard.org/a/documents/2013-Report-Card.pdf.

[3]“Obama Proposes Plan for Infrastructure Funding,” America’s Infrastructure Report Card, July 30, 2013, available at http://www.infrastructurereportcard.org/asce-news/obama-proposes-plan-for-infrastructure-funding/.

[4] “On a Crash Course: The Dangers and Health Costs off Deficient Roadways,” Pacific Institute for Research and Evaluation (2009), available at http://www.infrastructureusa.org/on-a-crash-course-the-dangers-and-health-costs-of-deficient-roadways/.

[5] See Igor Linkov, Daniel A. Eisenberg, Matthew E. Bates, Derek Chang, Matteo Convertino, Julia H. Allen, Stephen E. Flynn, and Thomas P. Seager, “Measurable Resilience for Actionable Policy,” Environmental Science & Technology 47, no. 18 (2013): 10108-10110. DOI: 10.1021/es403443n.

[6] Matthew D. Bartos and Mikhail V. Chester, “Impacts of Climate Change on the Electric Power Supply in the Western United States,” Nature Climate Change 5, (2015): 748-752. DOI: 10.1038/nclimate2648

[7] A conceptual framework for understanding infrastructure interdependencies is provided by Rinaldi, Steven M., James P. Peerenboom, and Terrence K. Kelly, “Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies,” Control Systems, IEEE 21, no. 6 (2001): 11-25. DOI: 10.1109/37.969131.

[8] Steven Flynn, “International Resilience Symposium: Understanding Standards for Communities and Built Infrastructure Resilience,” National Institute of Standards and Technology, Northeastern University’s Center for Resilience Studies and the Kostas Research Institute (2015), available at http://www.northeastern.edu/resilience/wp-content/uploads/2015/07/NIST.GCR_.15-917-37-2.pdf.

[9] Supported by NSF award number 1360509

[10] A paper is being developed on this topic at Arizona State, which is led by PhD student Changdeok Gim and his co-authors Clark Miller, Susan Spierre Clark, and Eric Kennedy.

[11] The lack of incentives and governance structures as a barrier to resilience was discussed by Steven Flynn, Director of the Center for Resilience Studies at Northeastern University, at the National Workshop on Resilience Research, October 22-23, 2015 in Washington DC. It is also discussed by Thomas P. Seager, “The Sustainability Spectrum and the Sciences of Sustainability,” Business Strategy and the Environment 176, no. 7 (2008): 444-453.

[12] Jeryang Park, Thomas P. Seager, Suresh C. Rao, Matteo Convertino, and Igor Linkov, “Integrating Risk and Resilience Approaches to Catastrophe Management in Engineering Systems,” Risk Analysis 33, no. 3 (2013). doi: 10.1111/j.1539-6924.2012.01885.x.

[13] Supra Note 10.

[14] Clark Miller, Tischa Munoz-Erickson, and Chad Monfreda, “Knowledge System Analysis,” Consortium for Science, Policy and Outcomes (2010), available at http://cspo.org/legacy/library/1210260959F83311826SI_lib_KnowledgeSystems.pdf.

[15] A paper is being developed at Arizona State on how Knowledge System Analysis relates to the SAAL resilience processes. This paper is led by PhD student Eric Kennedy and his co-authors Clark Miller, Susan Spierre Clark, and Changdeok Gim.

[16] Supported by NSF award number 1441352.

[17] This research is part of a pilot research project at Arizona State, which is supported by the US Navy and ASU Lightworks.