The goal of this study is to make the government/users decide rationally with regards to the problems of the weapon systems management. Therefore it is necessary to develop how much precisely and through what methods the system should be cost. That costing policies should be determined under the considerations of the estimating expense and the expected benefit due to the applications of cost informations. After that, it must also be decided where the cost informations are used. We can suggest the cost results be used to find the most reasonable system among alternatives, the best producer, the most benevolent policy for user, and so on.