Using game theory to optimize the allocation of defensive resources on a city scale to protect chemical facilities against multiple types of attackers

Chemical facilities in cities are under increasing threats from multiple types of intentional attackers, such as criminals, employees engaging in illegal conduct, and terrorist groups (Irish Republican Army, Hamas, and Al Qaeda, etc.). Each type of attacker differs from others in its attack purposes, attack strategies and tactics, and valuations of targets. This study extended our previous study from coping with only one type of attacker to multiple types by presenting a Bayesian game-theoretic method, which can help defenders to minimize their expected losses by optimizing the allocation of limited defensive resources. The applicability and reliability of the method were tested using five chemical plants in a city in China storing massive amounts of flammable, explosive and toxic chemicals as a case study. Through this case study, the advantages of the proposed method were validated by comparing the effects on the expected loss of different defensive strategies.