1、1GOM3Operations ManagementLayout24Basic Production LayoutslProcess LayoutlProduct LayoutlGroup Technology(Cellular)LayoutlFixed-Position Layout 3Layout TypesFoundryMilling machinesLathesGrindingPaintingDrillsOfficeWeldingForging(a)Layout of a job shop4Process Layoutl Advantages:general purpose and l
2、ess capital intensive less vulnerable to changes equipment utilization employee supervisionl Disadvantages:slower processing rates lost production time for setups more capital and space for inventory longer manufacturing lead times materials handling requires variable path devices production plannin
3、g and control more difficult5Layout TypesStation 1Station 2Station 3Station 4(b)Layout of a production line6Product LayoutlAdvantages:faster processing rateslower inventoriesinfrequent setupslDisadvantages:risk of layout redesignless flexibilityfor low volume,dedicated resources have low utilization
4、7Group Technology(a)Jumbled flows in a job shop without GT cellsDrillingDDDDGrindingGGGGGGMillingMMMMMMAssemblyAAAALathingReceiving and shipping LLLLLLLL8Group Technology(b)Line flows in a job shop with three GT cells Cell 3LMGGCell 1Cell 2Assembly areaAALMDLLMShippingDReceivingG9Group Technology(b)
5、Line flows in a job shop with three GT cells Cell 3LMGGCell 1Cell 2Assembly areaAALMDLLMShippingDReceivingG1034Group TechnologyBenefits1.Better human relations2.Improved operator expertise3.Less in-process inventory and material handling4.Faster production setup1135Group TechnologyTransition from Pr
6、ocess Layout1.Grouping parts into families that follow a common sequence of steps.2.Identifying dominant flow patterns of parts families as a basis for location or relocation of processes.3.Physically grouping machines and processes into cells.12Example:Process Flow Analysisl Assume that King Sports
7、 Products produces a variety of tennis rackets sequentially on four machines,and the times required on each machine for one typical racket are shown as follows:RawMaterialsMachine AFramer4 minutesMachine BHandler3 minutesMachine CStringer10 minutesMachine DFinisher2 minutesRacket13Example:Process Fl
8、ow Analysis%5.474019)10(421034inputoutputefficiencyThroughput time:4+3+10+2=19 minutesCycle time of the process:10 minutesIf King is willing to invest in another machine,which type should it purchase?%762519)5(521034How much more can you improve if you have more resources?14Example:Process Flow Anal
9、ysisRaw materials2-ton capacity1 load/dayTruck AParts300 cap.1.5Tons/day240Parts/dayStorage3500 lb.cap.Storage500 cap.Fabrication25 lb/component25 component/hrAssembly20 units/hrPackaging A5 min.process time30Parts/hr375Lb/hr15 Components/hr15Units/hr120Units/day80Units/dayPackaging B10 min.process
10、time40Units/dayTruck BThe bottleneck shifts around the facilityHow?1516Example-Line BalancinglYouve just been assigned the job of setting up an electric fan assembly line with the following tasks:TaskTime(Mins)DescriptionPredecessorsA2Assemble frameNoneB1Mount switchAC3.25Assemble motor housingNoneD
11、1.2Mount motor housing in frameA,CE0.5Attach bladeDF1Assemble and attach safety grillEG1Attach cordBH1.4TestF,G1617Precedence DiagramACBDEFGH23.2511.2.511.41lWhich process step defines the maximum rate of production?1718The bottleneckTaskTime(Mins)DescriptionPredecessorsA2Assemble frameNoneB1Mount s
12、witchAC3.25Assemble motor housingNoneD1.2Mount motor housing in frameA,CE0.5Attach bladeDF1Assemble and attach safety grillEG1Attach cordBH1.4TestE,GMax Production=Production time per dayBottleneck time=420 mins3.25 mins/unit=129 units1819We want to assembly 100 fans per dayRequired Cycle Time,C=Pro
13、duction time per periodRequired output per periodC=420 mins/day100 units/day=4.2 mins/unitWhat does this figure represent?19Theoretical Min.Number of Workstations,NN=Sum of task times(T)Cycle time(C)ttN=11.35 mins/unit4.2 mins/unit=2.702,or 3tWhy should we always round up?20The McGraw-Hill Companies
14、,Inc.,1998Irwin/McGraw-Hill2021Some Rules Well Follow for Loading WorkstationslPrimary:Assign tasks in order of the largest number of following tasks.lSecondary(tie-breaking):Assign tasks in order of the longest operating time 21ACBDEFGH23.2511.2.511.41Station 1Station 2Station 3TaskFollowersTime(Mins)A62C43.25D31.2B2 1E20.5F11G11H01.423The McGraw-Hill Companies,Inc.,1998Irwin/McGraw-Hill2233Efficiency of the Assembly LineEfficiency=Sum of task times(T)Actual number of workstations(Na)x Cycle time(C)Efficiency=11.35 mins/unit(3)(4.2mins/unit)=.901
