Assessment of Interdependencies between Communication and Information Technology Infrastructure and other Critical Infrastructures from Public Failure Reports

Failure in Communication and Information Technology Infrastructure (CITI) can disrupt the effective functionalities of many of the critical infrastructures. Conversely, failures in other infrastructures can also propagate to CITI and hence disrupt the operation of these interconnected systems. Understanding the origin of these failures, their propagation patterns and their impacts can give us important ideas about infrastructure interdependencies and can be used for secure and reliable infrastructure design and operation. In this research we have taken the approach to use public domain failure reports to identify these interdependencies. We have developed a methodology to collect and categorize these reports and defined a set of critical attributes to extract meaningful information from them. Using this approach we have analyzed 12 years of infrastructure failure reports from ACM's RISKS forum. Our results have shown interdependencies between CITI and other critical infrastructures in different dimensions, such as origin of failures, impacts of failures in spatial and temporal dimensions, how they have affected public safety; and how failures have propagated from one infrastructure to another. Results obtained from the analysis of real life failure cases, which happened over a considerable span of time, should be useful for infrastructure researchers and practitioners. This paper also discusses the difficulties while using public domain data in an academic research.