1 Online Student Guide OpusWorks 2016, All Rights Reserved Total Productive Maintenance
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OnlineStudentGuide
OpusWorks2016,AllRightsReserved
TotalProductiveMaintenance
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TableofContentsLEARNINGOBJECTIVES......................................................................................................................................2INTRODUCTION....................................................................................................................................................2MEETINGCUSTOMERDEMAND...............................................................................................................................................2UNPLANNEDDOWNTIME.........................................................................................................................................................3TPMDEFINITION&GOALS.....................................................................................................................................................3TYPESOFMAINTENANCE.........................................................................................................................................................3TPMARCHITECTURE................................................................................................................................................................4UNSCHEDULEDDOWNTIME.....................................................................................................................................................4
TYPESOFMAINTENANCE..................................................................................................................................5PREVENTIVEMAINTENANCE...................................................................................................................................................5CORRECTIVEMAINTENANCE...................................................................................................................................................5MAINTENANCEPREVENTION..................................................................................................................................................5BREAKDOWNMAINTENANCE..................................................................................................................................................6
OEEDETAILS.........................................................................................................................................................6OEEWORKSHEET.....................................................................................................................................................................7COMPONENTSOFTHESIXBIGLOSSES..................................................................................................................................8EQUIPMENTRELIABILITYMETRICS.......................................................................................................................................9FAILURERATE............................................................................................................................................................................9RELIABILITYMETRICS...........................................................................................................................................................10TPMMETRICSSUMMARY.....................................................................................................................................................10
THEFINALPILLAR.............................................................................................................................................10TPMINTHEOFFICE...............................................................................................................................................................11
©2016byOpusWorks.Allrightsreserved.Version5.5May,2016TermsofUseThisguidecanonlybeusedbythosewithapaidlicensetothecorrespondingcourseinthee-LearningcurriculumproducedanddistributedbyOpusWorks.NopartofthisStudentGuidemaybealtered,reproduced,stored,ortransmittedinanyformbyanymeanswithoutthepriorwrittenpermissionofOpusWorks.TrademarksAlltermsmentionedinthisguidethatareknowntobetrademarksorservicemarkshavebeenappropriatelycapitalized.CommentsPleaseaddressanyquestionsorcommentstoyourdistributorortoOpusWorksatinfo@OpusWorks.com.
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LearningObjectives
Uponcompletionofthiscourse,studentwillbeableto:• DescribetheprimarybenefitsgainedfromTotalProductiveMaintenance(TPM)• Identifyfourmajorcategoriesofmaintenance• DefineOverallEquipmentEffectiveness
Introduction
MeetingCustomerDemand
Let’sbeginwithasimpletruth:tobesuccessful,manufacturingcompaniesmustproducetheirproductsataratethatmeetscustomerdemand.Butwhatdomanufacturingcompaniesdowhentheyrunupagainstproblemsthataffecttheiroutputcapacity?Often,theyseektoincreaseovertime,addshifts,orpurchasenewequipment.Theseinvestmentsmayresultinshort-termfixes,buttheyrarelygettotherootcauseoftheproblem.
Companiescanresolveoutputissuesmoreeffectivelybyoptimizingtheperformanceoftheirexistingequipmenttoincreasemachineavailability,improvemachineperformance,andimproveoutputquality.Whenamachineinaprocessbreaksdown,itcancreatebottlenecksthataffectmanyotherstepsintheprocess.Iftheequipmentoperateswithoutbreakdownsandworkswellconsistently,theentireprocesswillrunmoresmoothly,everyone’sworkwillbeeasier,andthecompanywillbemoreprofitable.
Productionequipmentperformanceproblemscanbetracedtosixmajorlosses.Theseincludebreakdownloss,setupandadjustmentloss,cycletimeloss,machinestoppageduetopartsshortages,startuprejects,anddefectloss.UnplannedDowntime
Unplannedmachinedowntimecanaccountforasmuchas40%oflostproductioncapacityandcanconsumeasmuchas30%ofacompany’smaintenancebudget.Inatypicalmanufacturingprocess,machinesarerequiredtoruncloseto100%ofthetimetheyareavailableinordertomakeaproductionschedule.Thisleavesnotimeforpreventivemaintenanceandcauseswearandtearonthemachines,whichinturnleadstomanymoreproblems.Resultingproblemscanincludepoorqualityanddefects,variationindeliveryofpartstodownstreamoperations,bottlenecks,andaccumulationofinventoryinthefactory.
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TPMDefinition&Goals
TotalProductiveMaintenance(orTPM),ateamandshopfloor-basedinitiative,isaproactiveprocessthatfocusesonoptimizingtheeffectivenessofmanufacturingequipment.ThegoalsofTPMinclude:preventingequipmentbreakdownsthroughplanning;preventingproductdefectsandrejectsbasedonequipmentissues;improvingequipmenteffectivenessandefficiency;involvingandtrainingoperatorsinequipmentmaintenanceandbasicrepair;improvingequipmenttominimizemaintenanceand/ormakethemaintenanceandrepaireasier;andreducingcosts,includingthemoneyandspacetiedupwithsparepartsinventory.TypesofMaintenance
YouhavejustlearnedthedefinitionofTPMandthegoalsitseekstoachieve.Nowlet’slookathowTPMworks.TPMincludesfourmaintypesofmaintenance.Preventivemaintenancefocusesonproactivemaintenancetopreventbreakdowns.Correctivemaintenancefocuseson
equipmentimprovementsormodificationstopreventbreakdownsormakemaintenanceeasier.Maintenancepreventionfocusesonminimizingrequiredmaintenancebasedonequipmentdesignand/orinstallation.Breakdownmaintenancefocusesonrepairingbreakdowns.TPMArchitecture
Wewilldescribethefourmaintenancecategoriesinmoredetailsoon.Butfirst,let’slookattheoverallarchitectureofTPM.TPMstartswith6S.Problemscannotbeseenclearlywhentheworkplaceisdisorganized.Followingthe6Sprocessandorganizingtheworkplacewillhelptheteamuncoverproblemsthatmightotherwisebeoverlooked.Thinkof6SasthefirstlayerofthefoundationneededtosupportTPM.TheotherfoundationalpartsuponwhichTPMisbuiltaretheeliminationofwasteandcontinuousimprovement.ThesearetheprincipleswhichmustbeinplacetosupportthepillarsorcomponentsofTPM.Asyoucanseeinthemodelshownhere,themainpillarsofTPMincludethefourtypesofmaintenancealongwith“keystosuccess.”We’lltalkabout“keystosuccess”laterinthismodule.
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UnscheduledDowntime
TPMisconcernedwithreducingunscheduleddowntimeofproductionequipment.Butwhyisunscheduleddowntimesoimportant?Whatisitsrealimpactoncycletime,andhowdoesitinterferewithLean?
Considerthis:Manufacturingcompaniescannotproduceifthenecessaryequipmentisdownornotavailable.Further,timeandenergyarerequiredtomakeadjustmentsandrepairstotheequipment.Inefficientequipmentcanresultinlessproductorslowerthanprojectedproduction.Unscheduledbreakdowns,machinemalfunctions,andcomponentbreakagescangeneratebadproductandresultinwastedtimeforreprocessing.
So,whatcanmanufacturingcompaniesdotocleartheroadblockcausedbyunscheduleddowntime?Theycanestablishprocessestoensureproductionequipmentisavailablewhenneeded,andperformmaintenanceandupkeepproactivelyversusreactively.TypesofMaintenance
Asyounowknow,TPMfocusesonfourtypesofmaintenance:preventivemaintenance,correctivemaintenance,maintenanceprevention,andbreakdownmaintenance.Let’stakeacloserlookateachofthesetypes.PreventiveMaintenance
Preventivemaintenancefocusesonproactivemaintenanceactivities,suchasdailyorweeklycleaning,inspecting,oiling,andotherminorworktokeepequipmentinhealthycondition.Toensureearlydetectionofchangesinconditionthatrequirework,manyoftheseactivitiesarecarriedoutbyoperators.Aformofpreventivemaintenancecalledautonomousmaintenanceistheconceptthatthepeoplewhooperateamachineshouldmaintainthemachine,thedegreeofwhichdependsontheirleveloftrainingandexperience.Becausemachineoperatorsareusuallythefirstonestoknowwhensomethinghaschanged,theyareinthebestpositiontoperformmaintenanceorseekhelp.
Thegoalofpreventivemaintenanceistopreventequipmentfailureandextendmachinelifeinordertominimizeunscheduleddowntime,costs,andnegativeimpactonoperations.Equipmentlistings,historicperformance,andpredictionsareusedtoplan,schedule,andperformthenecessarymaintenanceactivities.Tosuccessfullycarry-outthistypeofmaintenance,ascheduleandcommitmentoftimearerequired.Intimesofstrongdemandandtightschedules,thiscanbecomedifficult,butthecommitmentisamust!
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CorrectiveMaintenance
Thefocusofcorrectivemaintenanceistoimproveequipmentorcomponentssothatpreventivemaintenancecanbecarriedoutmoreeasily.Theideasforimprovementaregenerallybasedoninputandsuggestionsfromoperation-basedteamsandotherstaffastheybecomeinvolvedinTPM.Bymakingmaintenanceeasierandmoreaccessible,correctivemaintenanceservestoimprovereliabilityandpreventbreakdowns.Machinemodificationsanddesignchangesaresignsofcorrectivemaintenanceinaction.Correctivemaintenancerequirescreativityandvaryinglevelsofflexibility.Someinvestmentoftimeandmoneymaybenecessarytomaketheneededchangestoequipment.Thesecostsarejustifiedbybalancinginvestmentwiththeexpectedreturnsinreliability,uptime,andeaseofmaintenance.MaintenancePrevention
Maintenancepreventionisbasedonactionsandmodificationsthatminimizerequiredmaintenance.Aswithcorrectivemaintenance,manyoftheseideascomefromtheTPMoperation-basedteams.Maintenancepreventionreducescostsandmakesequipmentmoreavailableforproductiveuse.Maintenancepreventionisoftenaccomplishedthroughchangestodesignand/orinstallation.Challengesofmaintenancepreventionmayincludeaninvestmentoftimeandmoneyandaneedforcreativityandflexibility.BreakdownMaintenance
Thefocusofbreakdownmaintenanceistorepairmachinesandequipmentwhentheybreak.Asmuchaspossible,theserepairsarecarriedoutbyoperators,withallnecessarytoolsandpartsreadilyavailable(think5S).Breakdownmaintenanceisonlyappropriateforequipmentinneedofimmediaterepairorforequipmentthatdoesnotsignificantlyaffecttheoperationorgeneratemuchlossotherthanrepaircosts.Forthistypeofmaintenancetobesuccessful,companiesmustidentifyequipmentthatfitsthiscategory;trainoperatorsandfloor-basedteamstodotherepairs;andensurenecessarytoolsandpartsareavailable.Akeychallengeistoavoidusingbreakdownmaintenancewhen
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preventivemaintenanceisthebetterchoice.Toooften,breakdownmaintenanceisincorrectlyusedasthedefaultmethod,causingmajordelaysandincreasesincost.Breakdownmaintenancecanbeclassifiedbasedonthedurationandcomplexityoftherepair.Forexample,minorstoppagescanberepairedbytheoperatoraccordingtoworkinstructionsandvisualaids.Minorbreakdownswouldrequireassistancefromaprocessexpertoraleadworker.Moredifficultbreakdownswouldrequireamaintenancepersonandmajorbreakdownscouldrequireoutsideassistancefromafieldtechnician.OEEDetails
OverallEquipmentEffectiveness(OEE)isaprocessusedtocharacterizetheoverallperformanceofasinglepieceofequipmentorevenanentirefactory.AkeymetricassociatedwithTPM,OEEwasdesignedtohighlightareasforfocusedimprovementandtomeasureandcommunicatetheeffectivenessofimprovements.OEEiscalculatedbymultiplyingAvailabilitybyPerformancerateandQualityrate.Let’slookatthiscalculationinmoredetail:Availableoperatingtimeisthetotalamountoftimeavailableforamachinetorunafteraccountingforplanneddowntimesuchaslunchbreaks.Whenyousubtractdowntimelossesduetoequipmentfailures,changeovertime,andmaterialshortages,you’releftwiththeactualrunningtime.Actualrunningtimebecomesthetargetoutputandisaffectedbyspeedlossessuchasreducedspeed,machinewear,andoperatorinefficiencies.Theactualoutputcanbeexpressedintermsofthetotalpiecestobeproducedandisaffectedbystartuplosses,scrap,andrework.Availabilityistheratiobetweenactualrunningtimeandtheavailableoperatingtime;performanceisaratiobetweenactualoutputandtargetoutput;andqualityisaratiobetweengoodpiecesandtotalpieces.Thesethreeratiosmultipliedtogether(AvailabilitytimesPerformancetimesQuality)equalOEE.
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OEEWorksheet
UsingaspreadsheettocalculateOEEmakesthejobabiteasier.Thisisatypicalspreadsheet,butcompaniescancreatetheirowntomeettheirneeds.
ComponentsoftheSixBigLosses
OneofthemajorgoalsofusingOEEaspartofTPMistoreduceand/oreliminatetheSixBigLosses,themostcommoncausesofefficiencylossinmanufacturing.Theyinclude:breakdownloss,setupandadjustmentloss,cycletimeloss,stoppageduetoshortages,startuprejects,anddefectloss.ThistableshowstherelationshipbetweeneachlossintheOEEcategory.Datacanbecollectedoneachofthesecausesoflosstoserveasabasisforcorrectiveaction.KaizenEventscanthenbedefinedtocorrectand/oreliminatetheproblems.
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EquipmentReliabilityMetrics
Unfortunately,manymaintenanceoperationsstilloperateontheprinciple,“ifitain’tbroke,don’tfixit!”Preventingbreakdownsfromhappeninginthefirstplaceisamuchbetterapproach.Reliabilitymetrics,whichareusedtomeasureandunderstandequipmentperformanceandmaintenancerequirements,arekeycomponentsofpreventivemaintenance.Equipmentreliabilitymetricsarederivedfromthreebasicmeasures:schedulehours(thenumberofhoursscheduledfortheequipmentperweek);numberofbreakdowns(thenumberoffailuresthatoccurperweek);andrepairtime(theamountoftimeittakestorepaireachbreakdown).Let’slookatanexample:Duringaoneweekperiod,aprocessrunsfortwoshiftsof40-hourseach.Duringtheweek,therearefourbreakdowns,whicharerepairedin115minutes,110minutes,40minutes,and135minutes,foratotalrepairtimeof400minutes.Thisinformationcanbeusedtocalculateseveralequipmentreliabilitymetrics.FailureRate
Failurerateisoneofthesimplestandmostusefulmetricsusedtodetermineequipmentperformance.Itcanbeapproximatedusinganyconvenienttimeinterval,suchasoneweek,onemonth,etcetera.FailurerateisdesignatedbytheGreekletterlambdaandisequaltothenumberoffailuresduringthedesignatedtimeperioddividedbythetotaloperatinghours.Asyoucanseefromthiscalculation,thefailurerateforourexampleis.063breakdownsperweek.
Anothersimplereliabilitymetric,meantimebetweenfailure(orMTBF),isusedtodeterminetheaverageamountoftimebetweenfailures.Thisisausefulmetricforlongperiodsoftime,butisnotsuitablefordailyorweeklymonitoring.Thisisbecauseiftherearenobreakdownsinagiventimeperiod,theMTBFcannotbemathematicallydefined.Forthisexample,let’sassumethetimeperiodisonemonth(ratherthantheoneweekperiodusedinthepreviousexample).Asyoucansee,MTBFiseasilycalculatedusingthesamemeasuresusedtodeterminefailurerate,butwiththedatainverted.Inthiscase,MTBFis15.83hours.
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ReliabilityMetrics
Meantimetorepair(orMTTR)isareliabilitymetricthatcanbederivedfromjusttwoofourthreebasicmeasures:numberofbreakdownsandrepairtime.Ausefulmetricformaintenance,itreflectsboththeseverityofthebreakdownsandtheeffectivenessoftherepairs.MTTRisequaltothesumoftherepairtimes,dividedbythenumberofbreakdowns.Inourexample,MTTRis100minutes(or1.67hours)perbreakdown.Reliabilityrateisametricusedtoshowtheprobabilitythatamachinewillrunforacertainnumberofhourswithoutbreakdown.Tocalculatethismetric,weusetheformula“R(t)=etothenegativelambdat.”Inthisformula,‘t’representsthedesignatednumberofhours,andasyourecall,“e”isaconstantequalto2.71828andlambdarepresentsfailureratewhich,aswesawearlier,isequalto.063breakdownsperhour.Therefore,inourexample,theprobabilitythatthemachinewillrunfor8hourswithoutbreakdownispoint60(or60percent).TPMMetricsSummary
AsummaryoftheOEEandreliabilitymetricsforourexampleshowsseveralareasforimprovement.Forinstance,itshowsthatthemachineisonlyavailabletooperate69%ofthetime,andwhenitdoesoperate,itonlyperformsat75%ofitscapacity.Thissummaryalsoshowsahighmachinefailurerate,withonlya60%chancethemachinewillrun8hourswithoutafailure.Trackingthesemetricsasimprovementprojectsarecompletedandimplementedwillhelpdeterminewhethertheimprovementsareworking.TheFinalPillar
Asyoulearnedatthebeginningofthismodule,thefourtypesofmaintenancearepillarsthatsupportTPM.ThefinalpillarofTPM,keystosuccess,encompassesseveralthings.First,managementatalllevelsmustunderstandthatinTPM,theroleofmaintenancechangesfromtroubleshootingandrepairingtopreventingfailure.Leadershipatalllevelsisalsoessential.Topmanagementsupport,middlemanagementbuy-inandleadership,andgoodcommunicationsarealsokeystosuccess.Goodtraining,includingawarenesstrainingatthebeginningoftheprogramanddetailedtrainingatalllevelsoftheorganization,isanotherimportantfactorofaproject’ssuccess.Additionally,agoodpreventivemaintenancesystemmustbeinplace,andinformationonmachineperformanceandmaintenancehistorymustbeavailable.
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EveryoneinvolvedinaTPMprojectmustbecommittedtoitsimplementation,andafull-timepersonshouldbededicatedtothetask.Manycompaniesfail,especiallyintheearlystages,whentheteamleaderhastosplittimewithothertasks.Followupisthefinalkeytosuccess.OnceanareaorapieceofmachineryisreadytolaunchTPM,thetaskhasjustbegun.99%ofitssuccesswilldependoncommunicationbetweenthecoordinator,management,andmachineoperators.Goodfollow-upisnecessarytobuildconfidencefortheTPMprojectandtoachievethemaximumbenefit.
TPMintheOffice
TPMfocusesonmachinesandequipmentthatproduceproductsforcustomers.Whilemachinesandequipment,suchascomputers,telephones,printers,andcopiersareusedinanofficeenvironment,theequipmentisnotprimarilyresponsibleforproducingtheproduct.Rather,theequipmentsupportstheservicesthatareprovided.Forthisreason,TPMisnotsuggestedforserviceandotherrelatedindustries.5SisbettersuitedtotheofficeenvironmentthanTPM,anditofferssimilarbenefitsandfocusesonmanyofthesameactivities.Forexample,inboth5SandTPM,teamsfocusoncleanworkareasandequipment;lookforitemsinneedofrepair;andputsuppliesandothernecessaryitemsinorder.In5S,asinTPM,itisalsoimportanttotrainallteammembersinbasicequipmentmaintenance(paperreplenishment,replacementoftonerandinkcartridges,etc.),andtoassignongoing5Sactivitiestoteammembers.
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