NASA:Reliability Management

RELIABILITYMANAGEMENT—-NASALewisResearchCenter

[size=3]本篇文章是美国国家航空和宇航行局的关于可靠性管理文章，高度概括了一下可靠性管理的工作内容，目标。

RELIABILITYMANAGEMENT
•Thedirectionandcontrolofthereliabilityactivitiesoftheorganizationincludingstaffing,providingfacilities(computers,softwareetc.),establishingreliabilitygoalsandpolicies,andthefacilitatingoftheinteractionofreliabilitypersonnelwiththeremainderofthe
organization.(Thisistheinstructorssuggesteddefinition–howcanitbeimproved?)

WhyBeneficial?
•Likequalitycontrol,theestablishmentofJIT,ISO9000certificationandtruestatisticalprocesscontrolintheorganization,reliabilitymusthaveunequivocaltop-downsupport.
•Withoutthis,thereliabilityfunction,willonly“begoingthroughthemotions.”
•Witheffectivesupportfuturebottomlinecostsandtotalcostofownershipcanbedrasticallyreduced.

Theresultantcostbenefitstothecompany,thoughdifficulttocapturewithtraditionalaccountingmethods,willincreaseproductivityupto40%ormore.

OBJECTIVES
Beabletoanswer(orperform):
•Whattypesofreliabilitymanagementstructuresarethere?
•Whataretheobjectivesofreliabilitymanagement?
•Whatarethekeyreliabilitydisciplines?
•Howdoesthereliabilitydisciplineinteractwiththerestoftheorganization?
•Describewhatactivitiesyouwouldsetupforareliabilityprogramtosupportaproject.Whatmetrics

wouldyouuse?
•Howdoreliabilityactivitiesbenefittheproject?
•Whatishumanengineeringandhowdoesthehumanelementaffectreliability?

Outline:Reliability
•TypesofReliabilityOrganizations.
•ReliabilityandSystemsEngineering.
•EstablishingaReliabilityProgram.
•ExamplesofReliabilityObjectives.
•MetricsforReliability.
•HumanReliability

ReliabilityOrganization:Staffing
•Needstafffamiliarwiththedesign,manufactureandtestingmethodologyoftheproductandfamiliar

withstatisticaltechniques.
•Useseniorstafffromengineeringorganizationswhoareintimatelyfamiliarwithproductandthe

historyoffailures/problemsencounteredwiththedesign,testandmanufactureoftheproduct.
•Useengineerswithformalreliabilityengineeringdisciplineasacomplementtotheabove.
•Alltheseengineersmustbecapableofhavingacloseworkingrelationshipwithdesignandtestandbe

capableofinteractingwiththeminawin-winatmosphere.
•Partofnormalengineeringtrainingrotation.

ReliabilityGoals
•Increasesystemeffectivenessto:________
•Increasesystemavailabilityto:________
•IncreaseMTBFto:________
•Reducewarrantycostsby:________
•Reducemaintenancecostsby:________
•Increasesystemefficiencyby:________
•Increasesystemtestingby:________

DESIGNFORRELIABILITY

ASSURANCE:RELIABILITYENGINEERING
PHASEAPHASEBPHASECPHASEDPHASEE
RELIABILITYMANAGEMENT—————————————–
MONITOR/CONTROLSUBCTR.
PROGRAMREVIEWS————————————————
PROBLEMREPORT&COR.,LL
FAILUREREVIEWBOARDS
RELIABILITYMODELING————————–
RELIABILITYALLOCATION———————-
RELIABILITYPREDICTION———————–
FAILUREMODE&EFFECTANALYSIS——–
CRITICALITEMSLIST———————-
FAULTTREEANALYSIS——————-
SNEAKCIRCUITANALYSIS————–
ELECTRONICTOLERANCE
MECH.PARTSANALYSIS
PARTSPROGRAM,UsingFailureRateData
EFFECTSTEST,STORAGE,HANDLING,etc.
TESTING:ENVIRONMENTALSTRESSSCRN.
RELB.GROWTHTESTS
RELB./QUAL.TESTPROGRAM
RELIABILITYGROWTHTESTING—–
PRAT
SOFTWARERELIABILITY&QUALITYASSURANCE

EstablishingaDesignforReliabilityProgram
•Determinethereliabilitygoalstobemet.
•Constructasymbolicrepresentation.
•Determinethelogisticssupportandrepairphilosophy.
•Selectthereliabilityanalysisprocedure.
•Selectthedatasourcesforfailureratesandrepairrates.
•Determinethefailureratesandrepairrates.
•Performthenecessarycalculations.
•Validateandverifythereliabilityresults.
•Measureactualreliability.

ExamplesofReliability
ObjectivesfortheTelecommunicationsIndustry
•Goalsshouldbeplacedinproperperspective.
•Largetelecommunicationsnetworks:
–Atleastonepieceofequipmentmaybe
downatalltimes.
–Theusermaynotknowthis.
–Operatorsconsiderthatasystemisdownonlywhenreportedtothem.
–Short,self-clearingoutagesmaygounreported.
•Reliabilityobjectivescanbedefineddifferentlyforvarioussystems.

ExamplesofReliabilityObjectivesfortheTelecommunicationsIndustry
ModuleorSystemObjective
TelephoneinstrumentMeantimebetweenfailures
ElectronickeysystemCompletelossofservice
Majorlossofservice
Minorlossofservice
PABXCompletelossofservice
Majorlossofservice
Minorlossofservice
Mishandledcalls
TrafficServicePositionSys.(TSPS)MishandledcallsSystemoutage
Class5officeSystemoutage
Class4officeLossofservice
Class3officeServicedegradation

CustomerSpecificationsTargets
•Thesatisfiedcustomersetstheperformanceand
availabilityrequirements.
•Telecommunicationsnetworksshouldperformunder
stress:
–Cablecuts.
–Lengthytrafficoverloads.
–Equipmentbreakdown.
•Coppercableandfiberopticstudieshaveshown:
–56%ofthecablepairsarecut.
–100%ofthefiberopticarecut.
•Cross-connectsandallocatablecapacityareusedtodynamicallyreconfigurethenetwork.

ReliabilityGrowthFromaCustomer’sPerspective
•GrowthMeasurementmustencompasstheentirelifecycleoftheproduct.
•Corporationswithawidescopeofproductand/orproductlinesshouldnotpresentoverallreliability
growthcurvesonanorganizationalbasis.Individualproductlinereliabilitygrowthpicturesshouldbe
presentedtoachievetotalcustomersatisfaction.

Becausethecustomer’sexperiencecanvarywiththematurityofasystem,reliabilitygrowthisanimportantconcepttothecustomerandshouldbeconsideredinthecustomer’spurchasingdecision.
•Thekeyistodefinethegoalsfortheproductorservicefromthecustomer’sperspectivewhile

reflectingontheactualsituationinwhichthecustomerobtainstheproductorservice.

ReliabilityMetrics
•Reliabilitygrowth
•Systemuptimeandavailability
•Reductionintotallifecyclecost.
•Failurereportsprocessed.
•Numberoflessonslearnedgenerated/published.
•Increasedincalculatedsystemreliability(increasedMTBF)throughrecommendations.
•Numberoffailuremodesidentifiedandeliminated(basedonpotentialforoccurrenceandseriousness
offailure).
•Others:Yoursuggestions!!!

ReliabilityGrowth:Howmuchhasthesystemimproved.

ReductioninLifeCycleCosts(BasedonImprovedReliability)

FailureReportsClosedandLessonsLearnedGenerated

GenerationandEliminationsofFailureModes,CRIT1,2,&3

SystemReliabilityeveryMonth

HumanReliability
•Humanreliabilitycanbedefinedas“theprobabilityofaccomplishingajobortasksuccessfullybyhumansatanyrequiredstageinsystemoperationswithinaspecifiedminimumtimelimit.”
•Itisthebridgebetweentheuserandtheproducer.
•Focusindesignincludeshardware,software,andhumanreliability.

HumanReliabilityDesignGoals:
•Designforimmunitytohumanerror
•Designforeasyhumaninterface.
•Designtobeuserfriendly.
•Proveoutmanualsandprocedures.
•Minimizethelikelihoodofhumanerror;especiallyerrorsthatleadtounsafeconditions.
•Developdesignchecklists.
•Reviewforcompletenessandclarity.

HumanError:WrongConnections
InElectricalHookup
•Problem:wrongconnectorsmatedafterrepairandunitsmiswired.
•Solution:Differentsizeconnectorsandcommoncolorwirethroughoutacablerun;alsounsymmetricalconnectors.HumanError:ScaldingfromWaterFaucets/Showers.
•Problem:Confusingknobs,colorsandon/offrotationaldirections.
•Solution:standardization:Hotonleft,Hotcoloredred,coldcoloredblue;clockwisetoclose(righthandscrew);thermaltemperaturelimiterinwaterdeliverysystem.Differentsizelabelsandattachmentpoints.

EasyHumanInterface
•Switcheslocatedongraphicalmodelofsystem.
•Switchesmountedinorderofuse,lefttoright.
•Graphicalpresentationsonscreensaswellastext.
•Singlepointdisconnectsforemergencysystems.
•Standardcolorsforconditions:red/yellow/green.
•Vocalwarningsofimproperconditions.
•Testsystemandlayoutforstereotypebehavior.
•Standardizelayouts.
•Mostfrequentlyusedcontrolsinfavorablepositions.

UserFriendly
•Eleganceofdesign.
•Hierarchyofoptions.Alloweasytouseseriesofoperationsandextendedoperationsseparatedfromthose.
•Proveoutdesignwithuntrainedpersonnel.
•Don’tskimponhumaninterface(e.g.qualityofmaterials,colors,seating,knobs,keyboards,screenquality,etc.
•Providerealtimetraining.
•Allowdefaultstohavenominaloperationofsystem.

TypesofHumanErrors
•Errorsofvision
•Errorsofinsufficientknowledge.
•Equipmentnotcalibratedproperly.
•Difficulttoinspect.
•Designforemergencysituations.
•Designfortypicalbehavior.

ProveOutManualsandProcedures
•UseFMEAandFaultTreestogenerateblockdiagramsofdiagnostics.
•Writemanualstohelpoperatorsandmaintenancepersonnel.Donotwritemanualstowritemanuals.
•Takeuninvolvedpersonnel,givethemamanual,LEAVE,andallowthemtotrytouseit.THENMAKE
REVISIONSandgiveittonewuninvolvedpersonnel.
•Giveclearwarnings,cautionsandsuggestions.
•Writewithlevelsofdetail.
•Beconciseandprecise.
•Revisethemanualwhenthesystemisrevised.
•Usechecklistsunlesstheoperatorscannameall50statesfrommemory.

ReliabilityManagement-Conclusions
•Determinethereliabilitygoalstobemet.
•Spelltheprogramrequirementsoutindetailaswellashowtheresultswillbeimplemented.
•Doreliabilityanalysesindraftformthatneverhavetobepublished(e.g.alertengineerstodangerousconditionsandhelpthemeliminatethembeforetheygetintothesystem).
•Validateandverifythereliabilityresults.
•Measureactualreliability.
•Humanreliabilityisakeyfactortoconsidertohaveasuccessful,reliableandsafeproduct.
•Reliabilityanalysisshouldcontinuethroughouttheproductlife-cycle.