物流系统中心选址模型简介.ppt

FacilitylocationmodelsfordistributionsystemdesignThedesignofthedistributionsystemisastrategicissueforalmosteverycompany.Theproblemoflocatingfacilitiesandallocatingcustomerscoversthecoretopicsofdistributionsystemdesign.Industrialfirmsmustlocatefabrication(制造厂)andassemblyplants(组装厂)aswellaswarehouses(仓库).Storeshavetobelocatedbyretailoutlets(零售网点).Theabilitytomanufactureandmarketitsproductsisdependentinpartonthelocationofthefacilities.Similarlygovernmentagencieshavetodecideaboutthelocationofofficesschoolshospitalsfirestationsetc.Ineverycasethequalityoftheservicesdependsonthelocationofthefacilitiesinrelationtootherfacilities.TypesofmodelsFacilitylocationmodelscanbebroadlyclassifiedasfollows:Modelswithoutcapacityconstraintsdonotrestrict(限制)demandallocation.Ifcapacityconstraintsforthepotentialsiteshavetobeobeyeddemandhastobeallocatedcarefully.Inthelattercasewehavetoexaminewhethersingle-sourcing(单来源)ormultiple-sourcing(多来源)isessential.Single-stagemodels(单阶段模型)focusondistributionsystemscoveringonlyonestageexplicitly.Inmulti-stagemodels(多阶段模型)theflowofgoodscomprisingseveralhierarchical(层次)stageshastobeexamined.Single-productmodels(单产品模型)arecharacterizedbythefactthatdemandcostandcapacityforseveralproductscanbeaggregatedtoasinglehomogeneousproduct.Ifproductsareinhomogeneoustheireffectonthedesignofthedistributionsystemhastobeanalyzedviz.multi-productmodels(多产品模型)havetobestudied.Locationmodelsbaseontheassumptionthatdemandisinelastic(无弹性的)thatisdemandisindependentofspatialdecisions.Ifdemandiselastic(弹性的)therelationshipbetweene.g.distanceanddemandhastobetakenintoaccountexplicitly.Inthelattercasecostminimization(成本最小)hastobereplacedthroughforexamplerev