Bài giảng Operations Management - Chapter 14: Material Requirements Planning (MRP) & ERP

Operations ManagementMaterial Requirements Planning (MRP) & ERP Chapter 141OutlineGLOBAL COMPANY PROFILE: COLLINS INDUSTRIESDEPENDENT INVENTORY MODEL REQUIREMENTSMaster Production ScheduleBills of MaterialsAccurate Inventory recordsPurchase Orders OutstandingLead Times for Each ComponentMRP STRUCTURE2Outline - ContinuedMRP MANAGEMENTMRP DynamicsMRP and JITLOT-SIZING TECHNIQUESEXTENSIONS IN MRPClosed-Loop MRPCapacity PlanningMaterial Requirements Planning II (MRP II)MRP IN SERVICES3Outline - ContinuedDISTRIBUTION RESOURCE PLANNING (DRP)ENTERPRISE RESOURCE PLANNING (ERP)Advantages and Disadvantages of ERP SystemERP in the Service Sector4Learning ObjectivesWhen you complete this chapter, you should be able to :Identify or Define: Planning bills and kitsPhantom billsLow-level codingLot sizing5Learning Objectives - ContinuedWhen you complete this chapter, you should be able to :Describe or Explain:Material requirements planningDistribution requirements planningEnterprise resource planningHow ERP worksAdvantages and disadvantages of ERP systems6Collins IndustriesLargest manufacturer of ambulances in the worldInternational competitor12 major ambulance designs18,000 different inventory items6,000 manufactured parts12,000 purchased partsMRP: IBM’s MAPICS 7Collins IndustriesCollins requires:Material plan must meet both the requirements of the master schedule and the capabilities of the production facilityPlan must be executed as designedEffective “time-phased” deliveries, consignments, and constant review of purchase methodsMaintenance of record integrity8InventoryProcess stageDemand TypeNumber & ValueOtherRaw Material WIPFinished GoodsIndependent DependentA Items B Items C ItemsMaintenance OperatingInventory Classifications9ItemMaterials WithIndependent DemandMaterials WithDependent DemandDemandSourceCompany CustomersParent ItemsMaterialTypeFinished GoodsWIP & Raw MaterialsMethod ofEstimatingDemandForecast & BookedCustomer OrdersCalculatedPlanningMethodEOQ & ROPMRPDependent versus Independent Demand10Requirements for Effective Use of Dependent Demand Inventory ModelsEffective use of dependent demand inventory models requires that the operations manager know the:master production schedulespecifications or bills-of-materialinventory availabilitypurchase orders outstandinglead times11Inputs to the Production PlanAggregate Production PlanMarketingCustomerDemandEngineeringDesignCompletionManagementReturn onInvestmentCapitalHumanResourcesManpowerPlanningProcurementSupplierPerformanceFinanceCash FlowProductionCapacityInventory12The Planning ProcessChange master production schedule?Execute material plansExecute capacity plansDetail capacity planMaterial requirements planMaster production scheduleAggregate production planChange requirements?Change capacity?RealisticNoYesChange production plan?Is capacity plan being met?Is execution meeting the plan?13Aggregate Production Plan1,2001,500Aggregate Production Plan (shows the total quantity of amplifiers10030075 watt amplifier450450500500150 watt amplifier100100100100240 watt amplifierMaster Production Schedule (Shows the specific type and quantity of amplifier to be produced87654321WeeksFebruaryJanuaryMonths14Typical Focus of the Master Production ScheduleMake to Order(Process Focus)Assemble to Order or Forecast(Repetitive)Stock to Forecast(Product Focus)Schedule finished productSteel, Beer, Bread Light bulbs, PaperPrint shopMachine shopFine dining restaurantExamples:Number of end itemsNumber of inputsTypical focus of the master production scheduleSchedule ordersSchedule modulesMotorcycles, autos, TVs, fast-food restaurant15List of components & quantities needed to make product Provides product structure (tree)Parents: Items above given levelChildren: Items below given levelShows low-level codingLowest level in structure item occursTop level is 0; next level is 1 etc.Bill-of-Material16Product Structure for “Awesome” A17Modular billsModules are final components used to make assemble-to-stock end itemsPlanning billsUsed to assign artificial parentReduces number of items scheduledPhantom billsUsed for subassemblies that exist temporarilySpecial Bills-of-Material18Bicycle(1)P/N 1000Handle Bars (1)P/N 1001Frame Assembly (1)P/N 1002Wheels (2)P/N 1003Frame (1)P/N 1004Bill-of-Material Product Structure Tree19Time-Phased Product Structure123456783 weeksF2 weeksEA1 week1 weekCG2 weeksD1 weekE2 weeksStart production of DD1 weekB2 weeks to produceMust have D and E completed here so production can begin on B20Manufacturing computer information system Determines quantity & timing of dependent demand items© 1995 Corel Corp.Material Requirements Planning (MRP)21Computer systemMainly discrete productsAccurate bill-of-materialAccurate inventory status99% inventory accuracyStable lead times© 1984-1994 T/Maker Co.MRP Requirements22Increased customer satisfaction due to meeting delivery schedules Faster response to market changesImproved labor & equipment utilizationBetter inventory planning & schedulingReduced inventory levels without reduced customer serviceMRP Benefits23Structure of the MRP SystemMaster ProductionScheduleBOMLead Times(Item Master File)Inventory DataPurchasing dataMRP planning programs (computer and software)MRP by Period ReportMRP by date reportPlanned order reportPurchase adviceException reportException report24Gross Material Requirements Plan for 50 “Awesome A” Speaker Kits25Forecast &Firm OrdersMaterialRequirementsPlanningAggregateProductionPlanningResourceAvailabilityMasterProductionSchedulingShopFloorSchedulesCapacityRequirementsPlanningRealistic?No, modify CRP, MRP, or MPSYesMRP and The Production Planning Process26MRP Systems - Input and OutputInventoryPurchasingMasterProductionScheduleBill ofMaterialsMaterialRequirementsPlanning SystemStatusPlanned Order& Other ReportsItem MasterData27Shows items to be producedEnd item, customer order, moduleDerived from aggregate planMaster Production ScheduleItem/WeekOct 3Oct 10Oct 17Oct 24Drills300200310300Saws300450310330Example28Derivation of Master ScheduleTherefore, these are the gross requirements for BPeriods1010123Master schedule for S sold directly405015ACB567891011Lead time = 4 for AMaster schedule for A402030SBC8910121113Lead time = 6 for SMaster schedule for S1040+10 = 5040502015+30= 451 2 3 4 5 6 7 8PeriodsGross requirements: B29MRP DynamicsSupports “replanning”Problem with system “nervousness”“Time fence” - allows a segment of the master schedule to be designated as “not to be rescheduled”“Pegging” - tracing upward in the bill-of-materials from the component to the parent itemThat a manager can react to changes, doesn’t mean he/she should30MRP and JITMRP - a planning and scheduling technique with fixed lead timesJIT - a way to move material expeditiouslyIntegrating the two:Small bucket approach and back flushingBalanced flow approach31Lot-Sizing TechniquesLot-for-lotEconomic Order QuantityPart Period BalancingWagner-Whitin Algorithm32MRP Lot-Sizing Problem: Lot-for-Lot Techniques33MRP Lot-Sizing Problem: EOQ Technique34MRP Lot-Sizing Problem: PPB Technique35Extensions of MRPClosed loop MRPCapacity planning - load reportsMRP II - Material Resource PlanningEnterprise Resource Planning36Closed Loop MRP37Extensions of MRPCapacity PlanningTactics for smoothing the load and minimizing the impact of changed lead time include:Overlapping - reduces the lead time, entails sending pieces to the second operation before the entire lot has completed the first operationOperations splitting - sends the lot to two different machines for the same operationLot splitting - breaking up the order and running part of it ahead of the schedule38Initial Resource Requirements/Smoothed Resource Requirements39Extensions to MRPEnterprise Resource PlanningMRP II with ties to customers and suppliers40MRP and ERP Information Flows, Integrated with Other Systems41MRP in ServicesCan be used when demand for service or service items is directly related to or derived from demand for other servicesrestaurant - rolls required for each mealhospitals - implements for surgeryetc.42Product Structure, Bill of Materials, Bill of Labor for Veal Picante43Distribution Resource PlanningDRP requires:Gross requirements, which are the same as expected demand or sales forecastsMinimum levels of inventory to meet customer service levelsAccurate lead timesDefinition of the distribution structure44