AN INTEGRATED MODEL SET FOR EVALUATING THE EFFECTS OF DESIGN ON AVAILABILITY AND LOGISTICS SUPPORT REQUIREMENTS OF WEAPON SYSTEMS

The life cycle cost of a weapon system is the total cost to the government of acquisition and ownership of that system over its full life. Life cycle cost can be partitioned into three basic categories. These categories are research and development cost, procurement cost, and operating and support cost. These costs are incurred in the order in which they are listed but it is important to realize the time at which these costs are determined and their relative magnitudes. Operating and support costs often exceed the sum of research and development cost and procurement cost. Even though these operating and support costs are incurred late in the life cycle process, they are design dependent and are determined early in the life cycle.;Costs are not the only dimension of the problem since system performance and availability are also important considerations. There are also questions concerning the operating policy and the support policy for the weapon system. The basic problem is to develop a methodology which can be used in the design phase of a weapon system's development to perform tradeoff analyses among cost, performance and availability.;The approach taken in this study is to combine existing models into a compatible set which can be used to perform some of these tradeoff analyses. The model set consists of the MOD-METRIC model, the Network Repair Level Analysis model and the Logistics Support Cost model. In particular, the relationship among availability and spares expenditures and the relationship of component failure rates to repair level decisions are investigated for certain components of the air refueling system of the KC-135A tanker aircraft. An incremental logistics support cost figure is also developed for this group of components.;This study shows that tradeoff analyses can be performed using a compatible set of models in such a way that their usefulness as a set exceeds that which can be attained when the models are exercised individually. The results of these analyses can be used in making component design decisions, choosing between alternative system designs and planning support requirements.