物流英语Ch8

MaterialHandlingChapter8chapteroutline(1)PartIMaterialHandlingSystemIntroductionofMaterialHandlingSystemTypesofMaterialHandlingSystemsMechanizedMaterialHandlingSystemsSemi-automatedMaterialHandlingSystemsAutomatedMaterialHandlingSystemsAutomatedStorage/RetrievalSystemschapteroutline(2)PartIIMechanizedMaterialHandlingEquipmentIntroductionLifttrucksWalkie-riderPalletTrucksTowlinesTowtractorwithtrailersConveyorsCarouselschapteroutline(3)PartIIISupplementaryReadingSafetyinMaterialHandlingWhatshouldworkersknowbeforehandlingmaterialPotentialhazardsforworkersPrecautionsshouldbetakenwhenmovingmaterialsmanuallyPrecautionsshouldbetakenwhenmovingmaterialsmechanicallySafetymeasuresregardingconveyorsSafetyPrecautionsforoperatingpoweredindustrialtrucksIntroductionofaterialHandlingSystemsMaterialhandlingequipmentsandsystemsoftenrepresentamajorcapitalinvestmentforanorganization.Likethedecisionsrelatedtothenumber,size,andlocationofwarehouses,materialhandlingcanaffectmanyaspectsofthefirm’soperation.TheMaterialHandlingInstitute,anindustrytradeassociationformanufacturersofmaterialhandlingequipmentsandsystems,hasestimatedthat:PartIMaterialHandlingSystemsThehardwareandsoftwareusedtomove,store,control,contain,andunitizematerialsinfactoriesandwarehousesexceed$50billionannually.Muchofthegrowthinsizeandvarietyofthemarketisfueledbymajorchangesintherequirementsofwarehouseanddistributionoperations(e.g.,reducedordercycletimes,reducedinventorylevels,reducedordersizes,SKUproliferation).TypesofMaterialHandlingSystemsMaterialhandlingsystemcanbeclassifiedasmechanized,semi-automated,automated,andinformation-directed.Acombinationoflaborandhandlingequipmentisutilizedinmechanizedsystemstofacilitatereceiving,processing,and/orshipping.Generally,laborconstitutesahighpercentageofoverallcostinmechanizedhandling.Automatedsystems,incontrast,attempttominimizelaborasmuchaspossiblebysubstitutingequipmentcapitalinvestment.Whenacombinationofmechanicalandautomatedsystemsisusedtohandlematerial，thesystemisreferredtoassemi-automated.Aninformation-directedsystemappliescomputerizationtosequencemechanizedhandlingequipmentanddirectworkeffort.Mechanizedhandlingsystemsaremostcommon,buttheuseofsemi-automatedandautomatedsystemsisincreasing.Themaindrawbacktoautomatedhandlingislackofflexibility.Onefactorcontributingtolowlogisticalproductivityisthatinformation-directedhandlinghasnotyettoachieveitsfullpotential.Thissituationispredictedtobedramaticallychangedduringthefirstdecadeofthe21stcentury.MechanizedMaterialHandlingSystemsMechanizedmaterialhandlingequipmenthasbeenthemainstayofthetraditionalwarehousingandwilllikelycontinuetobeimportantevenwiththemovetowardautomatedwarehousing.Mechanizedmaterialhandlingsystemsemployawiderangeofhandlingequipment.Suchequipmentcanbecategorizedaccordingtothefunctionsperformed,thatis,storageandorderpicking,transportationandsorting,andshipping.Semi-automatedMaterialHandlingSystemsMechanizedhandlingisoftensupplementedbysemiautomaticequipment.Typicalequipmentsutilizedinsemi-automatedhandlingsystemsincludesautomatedguidedvehiclesystems(AGVS),computerizedsortation,roboticsandvariousformsofliveracks.AutomatedMaterialHandlingSystemsForseveraldecadestheconceptofautomatedhandlinghasofferedgreatpotential.Initialautomatedhandlingeffortsfocusedonmastercartonorderselectionsystems.Recently,emphasishasshiftedtoautomatedhigh-risestorageandretrievalsystems.Theappealofautomationisthatitsubstitutescapitalequipmentforlabor.Inadditiontorequiringlessdirectlabor,anautomatedsystemoperatesfasterandmoreaccuratelythanitsmechanizedcounterpart.Table8-1showsthebenefitsofautomatedmaterialhandlingsystems.However,automatedsystemsarenotwithoutdisadvantages.Itsshortcomingsarethehighcapitalinvestment,maintenancecosts,inflexibilityandusertraining.AutomatedStorage/RetrievalSystemsAnautomatedstorage/retrievalsystemforpalletsiscommonlyreferredtoasaunitloadAS/RS.ItisdefinedbytheAS/RSproductsectionoftheMaterialHandlingInstituteasastoragesystemthatusesfixed-pathstorageandretrieval(S/R)machinesrunningononeormorerailsbetweenfixedarraysofstorageracks.AtypicalAS/RSoperationiscalledasinglecommand(SC)operation,involvingtheS/Rmachinespickingupaloadatthefrontofthesystem,transportingtheloadtoanemptylocation,deposingtheloadintheemptylocation,andreturningemptytotheinput/output(I/O)point.Adualcommand(DC)operationinvolvestheS/RmachinepickingupaloadattheI/Opoint,travelingloadedtoanemptylocation,depositingtheload,travelingemptytotheI/Opoint,anddepositingtheload.Thekeyideaisthatinadualcommand,thetwooperations,astorageandaretrieval,areaccomplishedbetweensuccessivevisitstotheI/Opoint.Information-directedmaterialhandlingSystem.Theconceptofinformation-directedisappealingbecauseitcombinesthecontroltypicalofautomatedhandlingwiththeflexibilityofmechanizedsystems.Information-directedsystemsusemechanizedhandlingcontrolledbyinformationtechnology.Twocommonexamplesofinformation-directedmaterialhandlingsystemsareRF-controlledequipmentandlight-directedoperations.NewWordsandExpressionsIntroductio