lec1-maintenance_definition__1_.ppt student

For Cipet student

1. Maintenance Definition
British Standard Glossary of terms (3811:1993)
defined maintenance as:
the combination of all technical and administrative
actions, including supervision actions, intended to
retain an item in, or restore it to, a state in which it
can perform a required function.

2. Maintenance Definition
maintenanceisasetoforganisedactivitiesthatare
carriedoutinordertokeepaniteminitsbest
operationalconditionwithminimumcostacquired.

3. Maintenance Activities
Activitiesofmaintenancefunctioncouldbeeither
repairorreplacementactivities,whicharenecessary
foranitemtoreachitsacceptableproductivity
conditionandtheseactivities,shouldbecarriedout
withaminimumpossiblecost.

4. Maintenance History
1.In the period of pre-World War II, people thought
of maintenance as an added cost to the plant which
did not increase the value of finished product.
Therefore, the maintenance at that era was
restricted to fixing the unit when it breaks because
it was the cheapest alternative

5. Maintenance History
2.DuringandafterWorldWarIIatthetimewhenthe
advancesofengineeringandscientifictechnology
developed,peopledevelopedothertypesof
maintenance,whichweremuchcheapersuchas
preventivemaintenance.
Inaddition,peopleinthiseraclassified
maintenanceasafunctionoftheproductionsystem.

6. Maintenance History
Fix the equipment
when it breaks
-Term terotechnology
introduced.
-Recognition of need to
present equipment
failures.
-Models for preventive
maintenance
developed.
-Increased awareness
of:
-Environment
-Safety
-Quality
-Need for reliable
equipment.
-Reduction in costs.
Pre-World War II Post-World War II 1980 Onwards
Time
Development of
Maintenance
Figure 2.2 Maintenance History
(Adapted From Shenoy, Bhadury 1998)

7. Maintenance History
3.Nowadays,increasedawarenessofsuchissuesas
environmentsafety,qualityofproductandservices
makesmaintenanceoneofthemostimportant
functionsthatcontributetothesuccessofthe
industry.
World-classcompaniesarein
continuousneedofaverywellorganised
maintenanceprogrammetocompeteworld-wide.

8. Maintenance Objectives
Maintenanceobjectivesshouldbeconsistentwithand
subordinatetoproductiongoals.
Therelationbetweenmaintenanceobjectivesand
productiongoalsisreflectedintheactionofkeeping
productionmachinesandfacilitiesinthebestpossible
condition.

9. Maintenance Objectives
•Maximisingproductionorincreasingfacilities
availabilityatthelowestcostandatthehighest
qualityandsafetystandards.
•Reducingbreakdownsandemergencyshutdowns.
•Optimisingresourcesutilisation.
•Reducingdowntime.
•Improvingsparesstockcontrol.

10. Maintenance Objectives
•Improvingequipmentefficiencyandreducingscrap
rate.
•Minimisingenergyusage.
•Optimisingtheusefullifeofequipment.
•Providingreliablecostandbudgetarycontrol.
•Identifyingandimplementingcostreductions.

11. Maintenance Objectives
PLANT
M
A
I
N
T
E
N
A
N
C
E
Reduce Breakdowns
Reduce Downtime
Improving Equipment
Efficiency
Improving Inventory
Control
Implementing Cost
Reduction
Maximising Production
Optimising Resources
Utilisation
Optimising Useful Life
of Equipment
Minimising Energy
Usage
Providing Budgetary
Control
Figure 2.3 Maintenance Objectives

12. Types of Maintenance
•RuntoFailureMaintenance(RTF)
•PreventiveMaintenance(PM)
•CorrectiveMaintenance(CM)
•ImprovementMaintenance(IM)
•PredictiveMaintenance(PDM)

13. Run to Failure Maintenance (RTF)
•Therequiredrepair,replacement,orrestoreaction
performedonamachineorafacilityafterthe
occurrenceofafailureinordertobringthis
machineorfacilitytoatleastitsminimum
acceptablecondition.
•Itistheoldesttypeofmaintenance.

14. Run to Failure Maintenance (RTF)
•Itissubdividedintotwotypes:
–Emergencymaintenance:itiscarriedoutasfast
aspossibleinordertobringafailedmachineor
facilitytoasafeandoperationallyefficient
condition.
–Breakdownmaintenance:itisperformedafter
theoccurrenceofanadvancedconsideredfailure
forwhichadvancedprovisionhasbeenmadein
theformofrepairmethod,spares,materials,
labourandequipment.

15. Run to Failure Maintenance (RTF)
•Disadvantages:
1.Itsactivitiesareexpensiveintermsofbothdirectand
indirectcost.
2.Usingthistypeofmaintenance,theoccurrenceofafailure
inacomponentcancausefailuresinothercomponentsin
thesameequipment,whichleadstolowproduction
availability.
3.Itsactivitiesareverydifficulttoplanandschedulein
advance.

16. Run to Failure Maintenance (RTF)
•Thistypeofmaintenanceisusefulinthefollowing
situations:
1.Thefailureofacomponentinasystemisunpredictable.
2.Thecostofperformingruntofailuremaintenanceactivities
islowerthanperformingotheractivitiesofothertypesof
maintenance.
3.Theequipmentfailurepriorityistoolowinordertoinclude
theactivitiesofpreventingitwithintheplanned
maintenancebudget.

17. Preventive Maintenance (PM)
Itisasetofactivitiesthatareperformedonplant
equipment,machinery,andsystemsbeforethe
occurrenceofafailureinordertoprotectthemand
topreventoreliminateanydegradationintheir
operatingconditions.

18. Preventive Maintenance (PM)
BritishStandard3811:1993Glossaryofterms
definedpreventivemaintenanceas:
themaintenancecarriedoutatpredetermined
intervalsoraccordingtoprescribedcriteriaand
intendedtoreducetheprobabilityoffailureorthe
degradationofthefunctioningandtheeffects
limited.

19. Preventive Maintenance (PM)
•Theadvantageofapplyingpreventivemaintenance
activitiesistosatisfymostofmaintenance
objectives.

20. Preventive Maintenance (PM)
•Thefactorsthataffecttheefficiencyofthistypeofmaintenance:
1.Theneedforanadequatenumberofstaffinthemaintenance
departmentinordertoperformthistypeofmaintenance.
2.Therightchoiceofproductionequipmentandmachinerythatis
suitablefortheworkingenvironmentandthatcantoleratethe
workloadofthisenvironment.
3.Therequiredstaffqualificationsandskills,whichcanbegained
throughtraining.
4.Thesupportandcommitmentfromexecutivemanagementtothe
PMprogramme.
5.TheproperplanningandschedulingofPMprogramme.
6.TheabilitytoproperlyapplythePMprogramme.

21. Preventive Maintenance (PM)
•Itisgoodforthosemachinesandfacilitieswhich
theirfailurewouldcauseseriousproductionlosses.
•Itsaimistomaintainmachinesandfacilitiesin
suchaconditionthatbreakdownsandemergency
repairsareminimised.
•Itsactivitiesincludereplacements,adjustments,
majoroverhauls,inspectionsandlubrications.

22. Preventive Maintenance (PM)
•Researcherssubdividedpreventivemaintenanceinto
differentkindsaccordingtothenatureofitsactivities:
•Routinemaintenancewhichincludesthosemaintenance
activitiesthatarerepetitiveandperiodicinnaturesuchas
lubrication,cleaning,andsmalladjustment.
•Runningmaintenancewhichincludesthosemaintenance
activitiesthatarecarriedoutwhilethemachineor
equipmentisrunningandtheyrepresentthoseactivitiesthat
areperformedbeforetheactualpreventivemaintenance
activitiestakeplace.

23. Preventive Maintenance (PM)
•Opportunitymaintenancewhichisasetofmaintenance
activitiesthatareperformedonamachineorafacilitywhen
anunplannedopportunityexistsduringtheperiodof
performingplannedmaintenanceactivitiestoothermachines
orfacilities.
•Windowmaintenancewhichisasetofactivitiesthatare
carriedoutwhenamachineorequipmentisnotrequiredfor
adefiniteperiodoftime.
•Shutdownpreventivemaintenance,whichisasetof
preventivemaintenanceactivitiesthatarecarriedoutwhen
theproductionlineisintotalstoppagesituation.

24. Corrective Maintenance (CM)
•Inthistype,actionssuchasrepair,replacement,or
restorewillbecarriedoutaftertheoccurrenceofa
failureinordertoeliminatethesourceofthis
failureorreducethefrequencyofitsoccurrence.
IntheBritishStandard3811:1993Glossaryofterms,
correctivemaintenanceisdefinedas:
themaintenancecarriedoutafterrecognitionandintendedto
putanitemintoastateinwhichitcanperformarequired
function.

25. Corrective Maintenance (CM)
•Thistypeofmaintenanceissubdividedintothree
types:
•Remedialmaintenance,whichisasetofactivities
thatareperformedtoeliminatethesourceoffailure
withoutinterruptingthecontinuityofthe
productionprocess.
Thewaytocarryoutthistypeofcorrectivemaintenanceis
bytakingtheitemtobecorrectedoutoftheproductionline
andreplacingitwithreconditioneditemortransferringits
workloadtoitsredundancy.

26. Corrective Maintenance (CM)
•Deferredmaintenance,whichisasetofcorrective
maintenanceactivitiesthatarenotimmediately
initiatedaftertheoccurrenceofafailurebutare
delayedinsuchawaythatwillnotaffectthe
productionprocess.
•Shutdowncorrectivemaintenance,whichisasetof
correctivemaintenanceactivitiesthatareperformed
whentheproductionlineisintotalstoppage
situation.

27. Corrective Maintenance (CM)
•Themainobjectivesofcorrectivemaintenancearethe
maximisationoftheeffectivenessofallcriticalplant
systems,theeliminationofbreakdowns,theeliminationof
unnecessaryrepair,andthereductionofthedeviationsfrom
optimumoperatingconditions.
•Thedifferencebetweencorrectivemaintenanceand
preventivemaintenanceisthatforthecorrective
maintenance,thefailureshouldoccurbeforeanycorrective
actionistaken.
•Correctivemaintenanceisdifferentfromruntofailure
maintenanceinthatitsactivitiesareplannedandregularly
takenouttokeepplant’smachinesandequipmentin
optimumoperatingcondition.

28. Corrective Maintenance (CM)
•Thewaytoperformcorrectivemaintenanceactivitiesisby
conductingfourimportantsteps:
1.Faultdetection.
2.Faultisolation.
3.Faultelimination.
4.Verificationoffaultelimination.
Inthefaulteliminationstepseveralactionscouldbetaken
suchasadjusting,aligning,calibrating,reworking,
removing,replacingorrenovation.

29. Corrective Maintenance (CM)
•Correctivemaintenancehasseveralprerequisitesin
ordertobecarriedouteffectively:
1.Accurateidentificationofincipientproblems.
2.Effectiveplanningwhichdependsontheskillsofthe
planners,theavailabilityofwelldevelopedmaintenance
databaseaboutstandardtimetorepair,acompleterepair
procedures,andtherequiredlabourskills,specifictools,
partsandequipment.
3.Properrepairprocedures.
4.Adequatetimetorepair.
5.Verificationofrepair.

30. Improvement Maintenance (IM)
•Itaimsatreducingoreliminatingentirelytheneedfor
maintenance.
•Thistypeofmaintenanceissubdividedintothreetypesas
follows:
1.Design-outmaintenancewhichisasetofactivitiesthat
areusedtoeliminatethecauseofmaintenance,simplify
maintenancetasks,orraisemachineperformancefromthe
maintenancepointofviewbyredesigningthosemachines
andfacilitieswhicharevulnerabletofrequentoccurrenceof
failureandtheirlongtermrepairorreplacementcostisvery
expensive.

31. Improvement Maintenance (IM)
2.Engineeringserviceswhichincludesconstructionand
constructionmodification,removalandinstallation,and
rearrangementoffacilities.
3.Shutdownimprovementmaintenance,whichisasetof
improvementmaintenanceactivitiesthatareperformed
whiletheproductionlineisinacompletestoppagesituation.

32. Predictive Maintenance (PDM)
•Predictivemaintenanceisasetofactivitiesthatdetect
changesinthephysicalconditionofequipment(signsof
failure)inordertocarryouttheappropriatemaintenance
workformaximisingtheservicelifeofequipmentwithout
increasingtheriskoffailure.
•Itisclassifiedintotwokindsaccordingtothemethodsof
detectingthesignsoffailure:
–Condition-basedpredictivemaintenance
–Statistical-basedpredictivemaintenance

33. Predictive Maintenance (PDM)
•Condition-basedpredictivemaintenancedependson
continuousorperiodicconditionmonitoringequipmentto
detectthesignsoffailure.
•Statistical-basedpredictivemaintenancedependson
statisticaldatafromthemeticulousrecordingofthe
stoppagesofthein-plantitemsandcomponentsinorderto
developmodelsforpredictingfailures.

34. Predictive Maintenance (PDM)
•Thedrawbackofpredictivemaintenanceisthatitdepends
heavilyoninformationandthecorrectinterpretationofthe
information.
•Someresearchersclassifiedpredictivemaintenanceasatype
ofpreventivemaintenance.
•Themaindifferencebetweenpreventivemaintenanceand
predictivemaintenanceisthatpredictivemaintenanceuses
monitoringtheconditionofmachinesorequipmentto
determinetheactualmeantimetofailurewhereas
preventivemaintenancedependsonindustrialaveragelife
statistics.

35. Types of Maintenance
MAINTENANCE
UNPLANNED
MAINTENANCE
(REACTIVE)
BREAKDOWNEMERGENCY
PLANNED
MAINTENANCE
(PROACTIVE)
CORRECTIVE
MAINTENANCE
REMEDIALDEFERRED
PREDECTIVE
MAINTENANCE
CONDITION -
BASED
STATISTICAL
-BASED
PREVENTIVE
MAINTENANCE
ROUTINE RUNNING
DESIGN -OUTENGINEERING
SERVICES
WINDOW
IMPROVEMENT
MAINTENANCE
SHUTDOWN
CORRECTIVE
SHUTDOWN
PREVENTIVE
SHUTDOWN
IMPROVEMENT
Shutdown Maintenance
OPPORTU-
NITY
Figure 2.4 Maintenance Types