An optimization model for modernizing the (U.S.) army’s helicopter fleet

The helicopter has grown in military stature for more than 40 years: its ascendancy has reformed the U.S. Army. Unfortunately, the current army helicopter fleet consists predominantly of Vietnam-era aircraft approaching the end of their useful lives. The authors have captured complex procurement and modernization tasks in an optimization-based decision support system, christened PHOENIX, which recognizes yearly operating, maintenance, retirement, service-life extension, and new procurement costs while enforcing constraints on fleet age, technology mix, composition, and budgets over a multi-year planning horizon. The army has applied PHOENIX to helitopters with such success that it has already been adapted to tactical wheeled vehicles and is under consideration for further applications.