A Near-Optimal Redundancy Allocation Strategy that Minimizes a System's Vulnerability to Hazardous Events and Malicious Attacks

Delivering continuous services in information infrastructures is a major challenge. For system or network administrators, redundancy allocation is one of the best strategies to ensure service continuity in the context of risk management, where the ultimate goal is to reduce potential threats to an acceptable level with limited resources. In this paper, we address the problem of reducing the vulnerability of a network to hazardous events and malicious attacks. We analyze the problem as a mixed, nonlinear, integer programming optimization problem with a min-max format. The solution approach, which is based on Lagrangean Relaxation and a subgradient method, solves this complicated problem effectively. We evaluate the scalability and applicability of the proposed heuristic via computational experiments on different network topologies and scales.