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Level OfRepairAnalysis
Level Of Repair AnalysisLifeCycleCost
LogisticsSupportAnalysisMaintenanceTask
AnalysisSparesModeling
FMECAReliability Centered
MaintenanceAnalysis
TheLevel Of Repair Analysis(LORA) is instrumental
inprovidinganoptimizedmaintenancephilosophybaseduponacostrational.
Thisanalysis canbeimplementedasastandaloneanalysis, butis generally
integratedintheLogisticsSupportAnalysisonaniterativebasis. TheLORA
canbeconsideredasatwo-stageprocessthatdetermineswhereanitemisdestinedtoberepairedandtowhatlevel.
TheresultsoftheLORA
processarebaseduponaneconomicandnon-economicrational.
TheLORA canbeconductedasaeconomical ornoneconomicalLORA,
orboth
If aneconomicalLORA (ELORA) is implemented,
thenasaprerequisiteannon-economical (orscreening)
processwouldbeimplemented. Thisscreeningprocesswill
minimizethecandidates,who aresubjecttoaELORA.
Generally
thecandidateswouldbeselectedandworkedinconjunctionwiththemaintenanceconcept.
Themaintenanceconceptwouldprovidedetailsaboutthelines(orlevel)
ofmaintenanceandwhattypeof
maintenanceactivitiesaretobeimplementedateachlineofmaintenance.
Theobjectiveof theELORA,whenperformedcorrectly, is
todeterminetheoptimumcostofrepair of anenditem/equipment,
bytakingintoconsiderationall
associatedsupportcostdrivers(e.g.,manpower, supportequipment,
training,transportation,etc.)
thatwouldberequiredateachlineofmaintenance. Thereis anelementin
theLORA processthatmustnotbeoverlooked,thatis
theSensitivityAnalysis. VaryingdifferentLCC costdriverswill
determinetheir impactonthemodel'srepairdecisions.
Non-Economical LORA
Thenon-economicLORA isbaseduponasetof predefinedquestions,
asgivenintheexampleLogic Chartbelow. This
logiccouldbemodifiedtotakeintoconsideration, other
maintenanceconstraints,asdictatedbyacustomer,
orcriteriasuchasoperational environmental restriction.
UsingtheLogic Tree, aresponseis
madetoeachquestion(asgivenbelow), followingthelogic.Thisprocesswill
lead itself toestablishthemaintenancestrategy andlevel of repair
for eachcorrectivemaintenancetask.Thequestionsidentify whichof
thefailedunitscanberemovedfromtheiroperational
positionswithaminimumamountof supportresources.
Whendeterminingif anitemor sub-itemshould
bereplacedand/orrepairedat1st line,considerationmustbegiventoall
aspectsof
themaintenancetask.Theseincludefaultdiagnostictechniques,accessibilityrequirements,
taskverification, elapsedtasktimes, disruptiontotheoperational
environmentetc.
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Logic fortheLevel of Repair Analysis(CM Tasks- Non-Economical
Criteria)
Questions
1. Isthedesignof theitemsuchthatrepair is feasible?2.
Aretheitem'smaintenancecharacteristicsandinstallationsuchthataremove/replace
strategy is feasibleatfirst line?3. Doestheitemhavelower level
subassemblies?4.
Doesitem'smaintenancecharacteristicspermitareplacementactionof
thesub-item?
5. Doestheitem'sconfigurationconsistof
subassembliesfrommultiplevendors?
Economical Level Of Repair Analysis (ELORA)
FollowingtheLORA, theELORA providesarecommendedrepair
strategybaseduponeconomicrational. Considerationis
alsogiventoanitem'smaintainabilityandphysical characteristics.
Therearemany ELORA modelsavailablethatcanbeusedfor
simpleandcomplexapplications.ForexampleMIL-STD-1390containsseveral
model suchasanAvionicsModel. Inthecaseofthismodel it
focusesonthefollowingsixmajorcostdrivers:
Inventory cost - includesinventoryadministrationcost,
attritioncost, transportation,etc.Support Equipment (SE) -
thecostof providingthenecessarySE (other thanstandardtoolsandSE)
for completingaparticularCM taskatagivenlevel ofmaintenance.
Space- requiredfor inventory.L abor cost - theassociatedcost for
personnel tocompleteeachrepair task.Trainingcost - thecostfor
upgradingandprovidingthenecessarytrainingtopersonnelperformingamaintenancetaskatagivenmaintenancesiteand/
orshop.Documentation - thecostfor
developingtherequireddocumentationfor eachof
themaintenanceoptions.
Thesealgorithmsrequirespecific inputdatafor
thesysteminherentsupportability
characteristicsanditsintended"Use"ordeploymentprofile.Systemlevel
dataincludesthesystem'sexpectedoperational life,operational
profile, andsitedata(distancesbetweenoperational centersandrepair
shop, includingthetotal number of thesefacilities.).
TheitemdataincludesMeanTimeBetweenFailures(MTBF), cost, repair
time, procurementleadtimesetc. It is
thesedataelementsprovidethelife-cyclecostdataandsystemdatausedfor
theELORAs.
