Modelling fortification strategies for network resilience optimisation

The ability of a system to tolerate disruptions and mitigate against malicious attacks is crucial in many applications, especially when a failure of the system can have huge economic and social consequences.

This concept of system resilience has drawn increasing research and practical interest. In their paper, 'external pageModelling Fortification Strategies for Network Resilience Optimization: the Case of Immunization and Mitigationcall_made', FRS researchers Dr Alberto Costa, Jidong Kang, Zhuochun Wu and their research partners, proposed a framework to define system resilience based on modelling of fortification strategies in the context of network interdiction problems.

They consider fortification strategies that address disruptions in two ways:

1. immunisation, where a certain disruption is not permitted to take place, and
   
2. mitigation, where the disruption occurs but is unable to impair significantly the system performance

Applying these two ways to the resilience optimisation problem (RES-OPT), they propose to maximise the capability of a system in fortifying against disruptions through immunisation and mitigation strategies. In this approach, they theoretically fortify a system against as powerful an attacker as possible. In addition, they also propose a cutting plane methodology to effectively solve the resulting optimisation problem, and apply it to a network flow with transmission-links fortification and an electricity transmission network problem in Southern China.

Analysing their results, they highight that RES-OPT yields good quality solutions in terms of both resilience and average costs, compared to other benchmark approaches.