面向负荷的生产控制与JIT课件.pptx

《面向负荷的生产控制与JIT课件.pptx》由会员分享，可在线阅读，更多相关《面向负荷的生产控制与JIT课件.pptx（21页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、Load-oriented manufacturing control just-in-time production for job shopsProduction Planning&Control1994 Vol.5.Wolfgang BechteHannover consultant firm1998/08/18 IntroductionA technique for job shops supporting the JIT concept -Using load-oriented order release,entry(Bechte,Kettner 1980)-Manufacturin

2、g control system is designed by Krautzig.-Implemented in many factories(Wiendahl,Bechte 19871991)Basic principles&technique for Load-oriented manufacturing control Detailed computational procedure refer to more theoretical publication written by Wiendahl(1993),Bechte(1988)content1.Objectives of load

3、-oriented manufacturing control2.Structure of load-oriented manufacturing control3.Basic concept in load-oriented manufacturing control4.Overview of a load-oriented manufacturing control system5.Example of the control system1.Objectives of load-oriented manufacturing controlReducing lead-time and WI

4、P.Keeping actual lead-time on stable lowest possible level.-Permanently In/Out put,inventory and average lead time of W/C are monitored and compared with their planned values in dynamic wayAt the same time determine Bottlenecks,short&mid-term capacity planningFurnishing realistic due-date scheduling

5、 and capacity planning2.Structure of load-oriented manufacturing controlFlow of orders for one single machineIllustrating events,a hierarchical controller levels,sectionsFigure 1.Funnel model of job shopMulti-level closed-loop control systemHigher controller level depends on theperformance of the lo

6、wer one.CompanyDISPOSITIONJob ShopMachineSalesDue DateLead timeUtilizationMfg.AssemblyReceivingShippingSupplierCustomerDisturbancesProd ScheduleLong Term CapacitiesOrder EntryMid termCapacitiesOrder releaseShort termCapacitiesOperation SequencesCapacities LoadingFigure2.Multilevel closed-loop contro

7、l system.3.Basic concept in load-oriented manufacturing control3.1 Basic relationship at a Work centerFour simple rules for regulating Input,Output,Inventory and Lead time1)constant inventory -keep In/Output the same on a avg.2)changing inventory -change input3)Average lead time -adjust In/Out ratio

8、4)Individual lead time to be even -apply FIFO rule while dispatchingAvg.lead time=Avg.Inv.Avg.OutputQueuing ordersAvg.OutputAvg.InputAvg.InventoryInputInitialInventoryAvg.Lead timeAvg.InventoryOutput curveInput curveOutputFinal InventoryControl PeriodLoadHoursTimedaysCompleted OrdersArriving OrdersF

9、igure 3.Basic relationship and throughput diagramBasic relationship at work center to plan the Input,Output,Inventory and Lead timeload limit=Planned output*(Planned lead time+Planning period)Planning period3.Basic concept in load-oriented manufacturing control3.2 Principle of Load limiting and Load

10、 conversionAdding LoadRemainingLoadLoadlimitPlannedInputActualInventoryPlannedlead timeCase Acase BTodayPlanning PeriodPlanned Inv.(Buffer)Plannedoutput(capacity)Figure4.Load limiting.In case that exceeding loads happensLoad limiting reject or prefer orders or variesRequired capacity=present load*pl

11、anning periodplanned lead time+planning periodRejectedLoadAllowedloadLoadlimitExceeding loadPresent LoadPlannedlead timeRequiredBufferRequiredcapacityFigure5.Short-term capacity planning using the load limitRequired Input CurveRequiredoutput curve.Order release should consider the work center loads

12、and capacitiesFour type of loads In case of B,D a statistical estimation is needed;Load conversion factordepreciation factor=planned output/Load limit =planning periodplanned lead time+planning periodLimiting and balance work in process by order release.Planned Inv.(I)(D)LoadlimitPlannedlead timeTod

13、ayPlanned Inv.(Buffer)Plannedoutput(capacity)(D)Planned Release(I)Ideal Released CurveFull loadConverted LoadFigure6.Derivation of conversion using the load limitA considering the available capacities of a short-term planning periods(12Week)Planned orders were scheduled backwardSelects periodically

14、those of the planned ordersStep1.Establish urgent ordersStep2.Release wotrkable ordersTime limit3.Basic concept in load-oriented manufacturing control3.3 Technique of load-oriented order release.If capacities is needed Load-oriented release require appreciate decisioncb aacabb acPlanning periodTime

15、limittodayTimeDaysDueOver dueFutureNon-UrgentOrder 4312WorkableWorkableUnworkableOmissibleABCWork centersLoadHoursLoad limitReleasedLoadRemainingLoadFigure 7.Steps of Load-oriented order release3.Basic concept in load-oriented manufacturing control3.4 Technique of load-oriented order entryThe ideas

16、of Load-oriented order entry is to avoid overloaded weeksChecks the scheduled operation dates against available capacities for a midterm planning horizon(ex 12 weeks)Realistic due dates are offered and the expected bottlenecks are indicated.Initiation capacity changes in advance if possibleOverload

17、weeks Free date.Cumulative LoadCumulative CapacityBacklogOverload WeeksUnderloadweeksPlanning horizonTodayTime weekFree DateOverloadPortion83%TotalLoad100%LoadhourFigure 8.Cumulative load and capacity of a work center.C is a critical work centerABCDEABCDEOverload WeeksTodayTime weekWorkcenterABCDEFr

18、ee DateOrder Lead TimeOperation Lead TimeRealistic Release DateRealistic Delivery DatePlanning HorizonFigure 9.Establishing a realistic delivery date of an order4.Overview of a load-oriented manufacturing control system1.Routing data2.Order data3.Item data4.Shop calendar5.Capacity data6.Transaction

19、data7.Control data:detailed tables for w/c and free definable group.PROGRAMTransactionDataPROGRAMControlDataPROGRAMShopCalendarProgramGraphsReportsPROGRAMOperationSequencingPROGRAMOrderReleasePROGRAMOrderEntryDIALOGCapacitiesDIALOGOperationCompleteDIALOGOrderReleaseDIALOGOrderEntryCapacitiesEntriesC

20、apacitiesReleaseCapacitiesSequencesGraphsReportsCONTROL SYSTEM(PC)BASIC SYSTEM(HOST)PLANNING SYSTEM(PC)Figure 10.Load-oriented manufacturing control system showing the data flow5.Example of the control system1.The method of basic throughput diagrams is extended(Figure 1 with diagrams)2.Operation Thr

21、oughput Element3.Planned and actual average lead time are computed for each inventory as well as average due-date dev.For release,input,output and deliveryEntryReleaseInputOutputDeliveryDispositionIndirectDirectDownstreamUpstreamOpenCycleTotal lead timeWait after operationTransport Wait before opera

22、tionSetupRunInteroperation timeProcess timeDirect Load time.4.Pump-building factory characteristics products 9000 pumps Manufactured parts 26000 different itemsManpower(Job shop)180 persons Work centers 130(mainly 2 shifts)Orders 350 per week Operations 4,5 per order(Max 20)Run times 3,7 per operati

23、on Lot sizes 30 per order(1-1000)Factory began to work with the new system in 1987Improvement(compared 1991 with 1987)Inventory was twice as high in 1987Most delivery higher than in 1987Cycle lead time(release delivery)were cut from almost 8weeks to 5weeksDue-date deviations 4.5 to 1 week(lateness)T

24、otal lead time(entrydelivery)14weeks to 9 weeksConclusionLoad-oriented manufacturing control system enables the factory 1.Reducing lead time and inventories 2.Keeping actual lead time on a planned level 3.Meeting the planned due dates 4.Maintain an appropriate work-center utilizationresults in safer

25、 scheduling foundation for JIT production1、有时候读书是一种巧妙地避开思考的方法。4月-234月-23Tuesday,April 25,20232、阅读一切好书如同和过去最杰出的人谈话。02:21:0402:21:0402:214/25/2023 2:21:04 AM3、越是没有本领的就越加自命不凡。4月-2302:21:0402:21Apr-2325-Apr-234、越是无能的人，越喜欢挑剔别人的错儿。02:21:0402:21:0402:21Tuesday,April 25,20235、知人者智，自知者明。胜人者有力，自胜者强。4月-234月-23

26、02:21:0402:21:04April 25,20236、意志坚强的人能把世界放在手中像泥块一样任意揉捏。25四月20232:21:04上午02:21:044月-237、最具挑战性的挑战莫过于提升自我。四月232:21上午4月-2302:21April 25,20238、业余生活要有意义，不要越轨。2023/4/252:21:0402:21:0425 April 20239、一个人即使已登上顶峰，也仍要自强不息。2:21:04上午2:21上午02:21:044月-2310、你要做多大的事情，就该承受多大的压力。4/25/2023 2:21:04 AM02:21:0425-4月-2311、自己要先看得起自己，别人才会看得起你。4/25/2023 2:21 AM4/25/2023 2:21 AM4月-234月-2312、这一秒不放弃，下一秒就会有希望。25-Apr-2325 April 20234月-2313、无论才能知识多么卓著，如果缺乏热情，则无异纸上画饼充饥，无补于事。Tuesday,April 25,202325-Apr-234月-2314、我只是自己不放过自己而已，现在我不会再逼自己眷恋了。4月-2302:21:0425 April 202302:21谢谢大家谢谢大家