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U.S.A.F. EDSA (European Distribution System Aircraft) Routing and Operating Location Selection Study.

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Final rept. 15 Dec 83-30 May 84,

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The European Distribution System Aircraft EDSA Study is defined as follows given a fleet of aircraft, a set of airbases to be transited for pick up and delivery of spare aircraft parts, and the stipulation that every base be transited twice each day, determine points operating locations at which to base the aircraft and a set of routes that meet the twice daily service criteria and minimize the sum of all route durations. The EDSA Study belongs to the general class of combinatorial problems known as location-allocation-routing. As such, all three parts of the problem cannot be solved simultaneously. Instead, standard practice is to first solve operating locations and then find routes using the locations selected. Multisource Weber theory, called the moment-sum method, is used to find the n sites for operating locations, where n is a decision variable. Given a set of operating locations, a routing procedure is used to find the shortest routes. The heuristic used in the EDSA model is based upon the Clarke-Wright savings method, with the Tillman-Cain multidepot extension. The computer code used, originally developed by Magnanti, Golden, and Nguyen, includes additional refinements, most notably Lins three-opt procedure as a route improvement post-processor, and efficient data structuring. The EDSA model required further extensions, including maximum route duration and an addition of a refueling requirement based on cumulative flight time between refuelings. The code was altered somewhat to utilize the CRAY-1S vector processing capability. Routing and output was piped to the DISSPLA graphics package to generate color route maps. Author

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  • Operations Research

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