Re-optimization of time-phased force deployment plans in response to emergent changes during deployment

Abstract

Although Operation Desert Storm has been heralded as a marvel in logistics, it was plagued with inefficiencies. Because of decreases in lift capacity since the Gulf War, and in anticipation of future operations that will likely evolve more rapidly, the U.S. needs better tools to develop efficient logistics plans. The Warfighting and Logistics Technology Assessment Environment (WLTAE) developed by Johns Hopkins Applied Physics Laboratory simulates the effects of logistical decisions on operational outcomes. WLTAE tracks the flow of units and materiel into ports in theater via a Time Phased Force Deployment Data List (TPFDDL) that remains fixed throughout the simulation, regardless of concurrent port damage. Responding to degradations of ports is an essential feature of robust planning, and requires continuous updates of the TPFDDL. We show how to modify a TPFDDL and its planned flow of supplies into a theater to account for changes in port capabilities. First, the, flows of materiel in the TPFDDL are aggregated into notional ships by a ship-loading heuristic. Second, these notional ships are rescheduled as' necessary to alternate ports and/or arrival dates by a ship reassignment heuristic. The solution quality of each heuristic is objectively assessed by comparison with a respective optimal solution to an equivalent mathematical programming model.