物资装备计划(MRP)(英文)(共26页).ppt

1、Material Requirement Planning (MRP)Contributors to MRP Joseph Orlicky George Plossl Oliver Wight American Production and Inventory Control SocietyWhat is MRP? Computerized Inventory Control Production Planning System Management Information System Manufacturing Control SystemWhen to use MRP Job Shop

2、Production Complex Products Assemble-to-Order Environments Discrete and Dependent Demand ItemsWhat can MRP do? Reduce Inventory Levels Reduce Component Shortages Improve Shipping Performance Improve Customer Service Improve Productivity Simplified and Accurate Scheduling Reduce Purchasing Cost Impro

3、ve Production Schedules Reduce Manufacturing Cost Reduce Lead Times Less Scrap and Rework Higher Production QualityWhat can MRP do? Improve Communication Improve Plant Efficiency Reduce Freight Cost Reduction in Excess Inventory Reduce Overtime Improve Supply Schedules Improve Calculation of Materia

4、l Requirements Improve Competitive PositionThree Basic Steps of MRP Identifying Requirements Running MRP Creating the Suggestions Firming the SuggestionsStep 1: Identifying the Requirements Quantity on Hand Quantity on Open Purchase Order Quantity in/or Planned for Manufacturing Quantity Committed t

5、o Existing Orders Quantity ForecastedStep 1: Important InformationMRP is. Company Sensitive Location Sensitive Date SensitiveStep 2: Running MRP Creating the Suggestions Critical Items Expedite Items Delay ItemsStep 3: Firming the Suggestions Manufacturing Orders Purchasing Orders Various ReportsOve

6、rview of the MRP SystemProduct Structure FileMaster Production ScheduleInventory Master FileMaterial Requirements PlanningManufacturing OrdersPurchase OrdersVarious ReportsMRP Inputs Product Structure File Master Production Schedule Inventory Master FileProduct Structure File Bill of MaterialsMaster

7、 Production Schedule Schedule of Finished Products Represents Production, not Demand Combination of Customer Orders and Demand Forecasts What Needs to be ProducedInventory Master File On-Hand Quantities On-Order Quantities Lot Sizes Safety Stock Lead Time Past-Usage FiguresMRP Process Schedules the

8、Production of all items using an MRP MatrixItem: Low-Level Code: Lot Size: Lead Time:PD12345Gross RequirementsScheduled ReceiptsProjected on HandNet RequirementsPlanned Order ReceiptsPlanned Order ReleasesMRP MatrixTerms Defined Item name or number for the item being scheduled Low-Level Code the low

9、est level of the item on the product structure file Lot Size order multiples of quantity Lead Time the time from when an order is placed to when it is received PD Past Due Time Bucket, orders behind scheduleTerms Defined Gross Requirements demand for an item by time period Scheduled Receipts materia

10、l already ordered Projected on Hand expected ending inventory Net Requirements number of items to be provided and when Planned Order Receipts net requirements adjusted for lot size Planned Order Releases planned order receipts offset for lead timesExample of the MRP ProcessItem: A Low-Level Code: 1

11、Lot Size: 25 Lead Time: 1PD12345Gross Requirements1015 25 25 30Scheduled Receipts25Projected on Hand20Net RequirementsPlanned Order ReceiptsPlanned Order ReleasesExample of the MRP ProcessItem: A Low-Level Code: 1 Lot Size: 25 min Lead Time: 1PD12345Gross Requirements1015 25 25 30Scheduled Receipts2

12、5Projected on Hand201020 20 20 15Net Requirements5510Planned Order Receipts25 25 25Planned Order Releases2525 25 30 25MRP Outputs Manufacturing Orders Purchasing Orders Various ReportsHubbell Lighting Case Manufactures Industrial Lighting Products Good-Quality Products Poor at Meeting Due Dates Work

13、 is Specialized for Each Customer Job Shop Environment Complex ProductsHubbell Lighting CaseBefore MRP Implementation Less than 75% of orders completed on timeAfter MRP Implementation 97% of orders completed on time 2% of orders completed with 1 to 2 days after due date Summary of MRPMRP is a. Computerized Inventory Control Production Planning Systemthat. Schedules Component Items as Neededwhich will. Track Inventory and. Help you in many other aspects of businessReferencesRussell, Roberta S., and Bernard W. Taylor III. Operations Management. 3rd Edition: Prentice Hal