Relax andfixheuristicstosolveone-stageone-machinelot-schedulingmodelsfor small-scale softdrinkplants

The productionplanningofregionalsmall-scalesoftdrinkplantscanbemodeledbymixedinteger models thatintegratelotsizingandschedulingdecisionsandconsidersequence-dependentsetuptimes and costs.Theseplantsproducesoftdrinksindifferentflavorsandsizesandtheyhavetypicallyonly one productionline.Theproductionprocessiscarriedoutbasicallyintwomainstages:liquidprepara- tion (stageI)andbottling(stageII).However,sincetheproductionbottleneckoftheseplantsisoften in stageII,inthisstudywerepresenttheproblemasaone-stageone-machinelot-schedulingmodel that considersstageIIasthebottleneckbutalsotakesintoaccountacapacityconstraintofstageI.To solve theproblem,weproposerelaxandfixheuristicsexploringthemodelstructureandweevaluate their computationalperformancessolvingdifferentprobleminstancesbasedonrealdataofaBrazilian small-scale softdrinkcompany.Thesolutionsobtainedarecomparedtothecompanysolutionsandthe solutions ofageneral-purposeoptimizationsoftware.