A geneticalgorithmbasedheuristicforschedulingofvirtualmanufacturing cells (VMCs)

Wepresentageneticalgorithm(GA)basedheuristicapproachforjobschedulinginvirtual manufacturingcells(VMCs).InaVMC,machinesarededicatedtoapartasinaregularcell,but machinesarenotphysicallyrelocatedinacontiguousarea.Cellconfigurationsarethereforetemporary, and assignmentsaremadetooptimizetheschedulingobjectiveunderchangingdemandconditions.We considerthecasewheretherearemultiplejobswithdifferentprocessingroutes.Therearemultiple machinetypeswithseveralidenticalmachinesineachtypeandarelocatedindifferentlocationsinthe shop floor.Schedulingobjectiveisweightedmakespanandtotaltravelingdistanceminimization.The schedulingdecisionsarethe(i)assignmentofjobstothemachines,and(ii)thejobstarttimeateach machine.ToevaluatetheeffectivenessoftheGAheuristicwecompareitwithamixedinteger programming(MIP)solution.Thisisdoneonawiderangeofbenchmarkproblem.Computational results showthatGAispromisinginfindinggoodsolutionsinveryshortertimesandcanbesubstituted in theplaceofMIPmodel.