物资装备计划(MRP)(1)

MaterialRequirementPlanning(MRP)ContributorstoMRP•JosephOrlicky•GeorgePlossl•OliverWight•AmericanProductionandInventoryControlSocietyWhatisMRP?•ComputerizedInventoryControl•ProductionPlanningSystem•ManagementInformationSystem•ManufacturingControlSystemWhentouseMRP•JobShopProduction•ComplexProducts•Assemble-to-OrderEnvironments•DiscreteandDependentDemandItemsWhatcanMRPdo?•ReduceInventoryLevels•ReduceComponentShortages•ImproveShippingPerformance•ImproveCustomerService•ImproveProductivity•SimplifiedandAccurateScheduling•ReducePurchasingCost•ImproveProductionSchedules•ReduceManufacturingCost•ReduceLeadTimes•LessScrapandRework•HigherProductionQualityWhatcanMRPdo?•ImproveCommunication•ImprovePlantEfficiency•ReduceFreightCost•ReductioninExcessInventory•ReduceOvertime•ImproveSupplySchedules•ImproveCalculationofMaterialRequirements•ImproveCompetitivePositionThreeBasicStepsofMRP•IdentifyingRequirements•RunningMRP–CreatingtheSuggestions•FirmingtheSuggestionsStep1:IdentifyingtheRequirements•QuantityonHand•QuantityonOpenPurchaseOrder•Quantityin/orPlannedforManufacturing•QuantityCommittedtoExistingOrders•QuantityForecastedStep1:ImportantInformationMRPis…..•CompanySensitive•LocationSensitive•DateSensitiveStep2:RunningMRP–CreatingtheSuggestions•CriticalItems•ExpediteItems•DelayItemsStep3:FirmingtheSuggestions•ManufacturingOrders•PurchasingOrders•VariousReportsOverviewoftheMRPSystemProductStructureFileMasterProductionScheduleInventoryMasterFileMaterialRequirementsPlanningManufacturingOrdersPurchaseOrdersVariousReportsMRPInputs•ProductStructureFile•MasterProductionSchedule•InventoryMasterFileProductStructureFile•BillofMaterialsMasterProductionSchedule•ScheduleofFinishedProducts•RepresentsProduction,notDemand•CombinationofCustomerOrdersandDemandForecasts•WhatNeedstobeProducedInventoryMasterFile•On-HandQuantities•On-OrderQuantities•LotSizes•SafetyStock•LeadTime•Past-UsageFiguresMRPProcess•SchedulestheProductionofallitemsusinganMRPMatrixItem:Low-LevelCode:LotSize:LeadTime:PD12345GrossRequirementsScheduledReceiptsProjectedonHandNetRequirementsPlannedOrderReceiptsPlannedOrderReleasesMRPMatrixTermsDefined•Item–nameornumberfortheitembeingscheduled•Low-LevelCode–thelowestleveloftheitemontheproductstructurefile•LotSize–ordermultiplesofquantity•LeadTime–thetimefromwhenanorderisplacedtowhenitisreceived•PD–PastDueTimeBucket,ordersbehindscheduleTermsDefined•GrossRequirements–demandforanitembytimeperiod•ScheduledReceipts–materialalreadyordered•ProjectedonHand–expectedendinginventory•NetRequirements–numberofitemstobeprovidedandwhen•PlannedOrderReceipts–netrequirementsadjustedforlotsize•PlannedOrderReleases–plannedorderreceiptsoffsetforleadtimesExampleoftheMRPProcessItem:ALow-LevelCode:1LotSize:25LeadTime:1PD12345GrossRequirements1015252530ScheduledReceipts25ProjectedonHand20NetRequirementsPlannedOrderReceiptsPlannedOrderReleasesExampleoftheMRPProcessItem:ALow-LevelCode:1LotSize:25minLeadTime:1PD12345GrossRequirements1015252530ScheduledReceipts25ProjectedonHand201020202015NetRequirements5510PlannedOrderReceipts252525PlannedOrderReleases2525253025MRPOutputs•ManufacturingOrders•PurchasingOrders•VariousReportsHubbellLightingCase•ManufacturesIndustrialLightingProducts•Good-QualityProducts•PooratMeetingDueDates•WorkisSpecializedforEachCustomer•JobShopEnvironment•ComplexProductsHubbellLightingCaseBeforeMRPImplementation•Lessthan75%oforderscompletedontimeAfterMRPImplementation•97%oforderscompletedontime•2%oforderscompletedwith1to2daysafterduedateSummaryofMRPMRPisa…..•ComputerizedInventoryControl•ProductionPlanningSystemthat…..•SchedulesComponentItemsasNeededwhichwill…..•TrackInventoryand…..•HelpyouinmanyotheraspectsofbusinessReferencesRussell,RobertaS.,andBernardW.TaylorIII.OperationsManagement.3rdEdition:PrenticeHall,2000Grubbstrom,RobertW.MaterialRequirementsPlanningandManufacturingResourcePlanning.03/12/2002.,Inc.System2000MRP.03/12/2002.://www.inventorysolutions.org/def_mrp.htm.