Applying a Fix-and-Relax Heuristics to US Navy Force Structure Planning

Abstract : Capital Investment Planning Aid (CIPA) is an optimization-based decision support system created for the U. S. Navy to help plan yearly force structure procurement and retirement. CIPA constraints include yearly industrial and budget limits, as well as mission inventory and force mix requirements. Over a 30-year planning horizon, CIPA helps plan over $1 trillion. Several approaches have been proposed and implemented to solve the CIPA core, a mixed-integer linear program (MILP). Unfortunately, some of these MILPs cannot be solved in a reasonable amount of time using general-purpose commercially available optimization software. This thesis presents a new MILP-based heuristic technique, fix-and-relax, that yields good quality solutions and reduces the computational solution time for our set of realistic test cases.