Multi-objective optimizationforinventorycontrolintwo-levelassemblysystems under uncertaintyofleadtimes

Supply planningfortwo-levelassemblysystemsunderleadtimeuncertaintiesisconsidered.Itissup- posed thatthedemandforthefinishedproductanditsduedateareknown.Theassemblyprocessateach level beginswhenallnecessarycomponentsareininventory.Aholdingcostateachlevelappearsifsome components neededtoassemblethesamesemi-finishedproductarrivebeforebeginningtheassemblyat this level.Itisassumedalsothatthecomponentleadtimeisarandomdiscretevariable.Theobjective is tofindthereleasedatesforthecomponentsatlevel2inordertominimizetheexpectedcomponent holding costsandtomaximizethecustomerservicelevelforthefinishedproduct.Forthisnewproblem, we considertwomulti-objectiveapproaches,whicharebothbasedongeneticalgorithms.Theyareevalu- ated withavarietyofsupplychainsettings,andtheirrespectiveperformanceisreportedandcommented. These twoheuristicspermittedtoobtaininterestingresultswithinareasonablecomputationaltime.