A risk informed decision framework for risk management of infrastructure systems against terrorist attacks

This paper presents a risk assessment framework to assist stakeholders of critical assets with allocating limited budgets for enhancing their security against terrorist attack. Its key contributions are the introduction of the notion of partial neutralization of attackers by defenders, estimation of total loss from successful, partially successful, and unsuccessful actions of attackers at during an attack, and inclusion of the effects of these losses on the choices made by terrorists at various stages of the attack. The proposed framework is demonstrated with an example of security risk assessment of a U.S. commercial airport, in which a set of plausible threat scenarios and risk mitigation options are considered. It is found that a combination of providing blast-resistant cargo containers and a video surveillance system on the airport perimeter fence is the best risk management option based on minimum expected cost over a 10 year service period.