Bilevel modelforproduction–distributionplanningsolvedbyusingant colony optimization

This paperaddressesahierarchicalproduction–distributionplanningproblem.Therearetwodifferent decision makerscontrollingtheproductionandthedistributionprocesses,respectively,thatdonot cooperatebecauseofdifferentoptimizationstrategies.Thedistributioncompany,whichistheleaderof the hierarchicalprocess,controlstheallocationofretailerstoeachdepotandtherouteswhichserve them. Inordertosupplyitemstoretailers,thedistributioncompanyordersfromthemanufacturing companytheitemswhichhavetobeavailableatthedepots.Themanufacturingcompany,whichisthe followerofthehierarchicalprocess,reactstotheseordersdecidingwhichmanufacturingplantswill produce them.Abilevelprogramisproposedtomodeltheproblemandanantcolonyoptimization based approachisdevelopedtosolvethebilevelmodel.Inordertoconstructafeasiblesolution,the procedureusesantstocomputetheroutesofafeasiblesolutionoftheassociatedmulti-depotvehicle route problem.Then,underthegivendataondepotneeds,thecorrespondingproductionproblemof the manufacturingcompanyissolved.Globalpheromonetrailupdatingisbasedontheleaderobjective function,whichinvolvescostsofsendingitemsfromdepotstoretailersandcostsofacquiringitems from manufacturingplantsandunloadingthemintodepots.Acomputationalexperimentiscarriedout to analyzetheperformanceofthealgorithm.