The strategy of Protection of vital facilities in the presence of attacks with varying severity levels

Today, vital infrastructure of security systems, are at risk of deliberate attacks and to provide the necessary preparations and an appropriate response to the attacks, strengthening the vital infrastructure is considered. In this paper, a special type of strengthening the vital infrastructure is discussed that in which before they are constructed, there would be planning about strengthening them. The case is formulated as a two-level planning that in high level, the defender is looking for minimizing the total cost, considering which facilities are built, and each facility, in terms of pre-attack, services which costumer and in terms of post-attack, how many defenders assigned to each facility. While at a low level, (the attacker) is looking for imposing the maximum cost to the system considering which facility and at what level of severity, is attacked. To resolve the case, a meta-heuristic ways based on simulated annealing method suggested and by solving an example and compare its results with the results of the exact solution, the effectiveness of the method has been tested.