Doing Quantitative Assessment of Infrastructure System Resilience

A study by Cen Nan and Giovanni Sansavini investigated infrastructure resilience and proposed a quantitative method for assessing technical system resilience.

Researchers seeking to define the resilience of infrastructure systems through a comprehensive literature review have concluded that the definition of resilience is still evolving.

For this study, they have used this definition of resilience as the ability of the system to withstand a change or a disruptive event even by reducing the initial negative impacts (absorptive capacity), adapting itself to them (adaptive capacity), and recovering from them (restorative capacity).

The three essential resilience features are these three capacities: absorptive, adaptive, and restorative.  

Engineered infrastructures have become interconnected and integrated in recent years, making for a complex system. Failure in one area can quickly cascade into other areas. A quantitative assessment method is required to fully understand the system’s resilience and performance.  

The paper presented two quantitative methods to measure resilience: a hybrid modelling approach and the time-dependent quantifiable
metric for resilience measurement in the context of engineered infrastructure.  

To test the feasibility and applicability of the two quantitative methods, the researchers applied it to the Swiss electric power supply system (EPSS) as the exemplary system after a natural hazard or a disruption.  The result shows that both strategies can significantly improve the system’s resilience, although they have varying effects on resilience capacities.

These resilient assessment methods not only quantify the system’s behaviour but also provide insights into different phases of disruptions, such as mitigation, adaptation, and recovery.  

The goal is for decision-makers to develop efficient mitigation and protection strategies for the long-term maintenance and retrofit resilience of infrastructures.

There is a further research opportunity to expand the capabilities of this method to other domains and to include resilience costs to systems, understanding that disruption-resilient systems will have lower costs than less resilient ones.

Climate change is predicted to bring more disruptions and extreme natural events. So, the goal of having a quantitative method for assessing resilience in infrastructure will also help implement climate adaptation and mitigation strategies for resilient infrastructure that could withstand and quickly recover from disruptions.