The fragility of interdependency

A study of failures in interconnected networks highlights the vulnerability of tightly coupled infrastructures and shows the need to consider mutually dependent network properties in designing resilient systems.

Abstract

A study of failures in interconnected networks highlights the vulnerability of tightly coupled infrastructures and shows the need to consider mutually dependent network properties in designing resilient systems. On 28 September 2003, Italy suffered a near-nationwide power cut (Sicily was spared) that also brought down the Internet. Buldyrev et al. take this event, typical of a number that have occurred worldwide in recent years, and examine how such a cascade of failures involving independent networks can occur. They find that, surprisingly, a broader degree of distribution increases the vulnerability of interdependent networks to random failure — the opposite of what happens in a single network. This highlights the need to consider interdependent network properties when designing robust networks if a random failure is not to have catastrophic results.