The State and the Threat of Cascading Failure Across Critical Infrastructures: The Implications of Empirical Evidence From Media Incident Reports

Abstract

The threat of cascading failures across critical infrastructures has been identified as a key challenge for governments. Cascading failure is seen as potentially catastrophic, extremely difficult to predict and increasingly likely to happen. Infrastructures are largely privately operated and private actors are thought to under-invest in mitigating this threat. Consequently, experts have demanded a more dominant role for government, including the use of regulation. Empirical evidence on cascading failure is, however, extremely scarce. This paper analyses new data drawn from news reports on incidents. We find that, contrary to current thinking, cascades are not rare. Neither do they indicate a wide array of unknown dependencies across infrastructures. Rather, we find a small number of focused, unidirectional pathways around two infrastructures: energy and telecommunications. We also found that most cascades were stopped quickly, in contrast to the oft-cited 'domino effect'. These findings undermine the case for more intrusive public oversight of critical infrastructures.

Modelling Dependencies Between Critical Infrastructures

“…A more recent empirical study [11], shows that events can been classified as cascade initiating (i.e., an event that causes an event in another CI), cascade resulting (i.e., an event that results from an event in another CI), and independent (i.e., an event that is neither a cascade initiating nor a cascade resulting event). The empirical findings indicate that:…”

“…Using a dataset on CI disruption incidents, empirical analysis [10,11] showed that interdependencies-mutual dependencies-seldomly occur. Newer analysis shows that the only interdependencies that are mentioned in press reports occur at a lower, component or subsystem, level of abstraction.…”

Using Centrality Measures in Dependency Risk Graphs for Efficient Risk Mitigation

“…Regardless of the underlying methodology, risk assessors would have a priori knowledge or intuition about the most important nodes in cascading failure scenarios. For example, empirical results show that energy nodes and information and communications nodes are the most common cascade initiators [15].…”

“…In the case of a dependency risk graph, nodes with high closeness tend to be part of many dependency chains; sometimes these nodes may even initiate dependency chains. Since cascading effects tend to affect relatively short chains (empirical evidence indicates that cascades rarely propagate deeply [15]), nodes with high closeness centrality would have larger effects on the overall risk of dependency chains than nodes with low closeness centrality. To formalize this idea, consider Equation (1) that computes the cumulative risk of a dependency chain: the closer a node is to the initiator of a cascading event, the greater the effect it has on the cumulative dependency risk.…”

“Water, Water, Every Where”: Nuances for a Water Industry Critical Infrastructure Specification Exemplar

“…However, threats in the quality of water distribution have also been identified due to loss of pressurised water, aging infrastructure, as well as vulnerabilities in interdependent infrastructure [3,4,5]. While case studies provide a means of disseminating nuances to the broader research and practitioner communities,it would be useful to share such insights using a format suitable for evaluating new innovation by researchers, or products and services by practitioners.…”