In this study, the required life cycle cost is evaluated in consideration of the equipment`s availability during its life cycle. In order to meet the maximum availability required by the process, the failure cost and life cycle cost is assessed, The optimal equipment selection method is presented according to the analysis of the failure cost and life cycle cost. For the systems in which equipments are connected serially, the optimal equipments are selected by minimizing the life cycle cost and satisfying the required system availability goal. In addition, the selection methods and life cycle cost are analyzed according to the cost variation of the equipment. By using the life cycle evaluation procedure, the failure cost and maintenance cost needed during the life cycle of the equipment can be presented.