Engineering Design Handbook - Maintainability Engineering Theory and Practice

291 Pages·17.362 MB·291\291

AMC PAMPHLET' AMCP 706-133
ENGINEERING DESIGN
HANDBOOK
MAINTAINABILITY
ENGINEERING
THEORY AND
PRACTICE
HEADQUARTERS, US ARMY MATERIEL COMMAND JANUARY 1976
AMCP706-133
PREFACE
The Engineering Design Handbooks of the US Army Materiel Command have
evolved over a number of years for the purpose of making readily available basic
information,technical data, andpracticalguidesforthedevelopmentofmilitaryequip
ment.
This handbook was prepared by Igor Bazovskyand Associates, Inc., of Sherman
Oaks, California, for the Engineering Handbook Office of Duke University, prime
contractorto the US Army Materiel Command. Itwas completed through the coor
dinated efforts of Mr. Bazovsky, Sr., and the Engineering Handbook Office of the
Research Triangle Institute, prime contractor to the US Army Materiel Command.
Technical guidance wasprovided byan Ad Hoc Working Groupunderthe chairman
ship of Mr. H. J. Bukowski, Headquarters, US Army Materiel Command.
Igor Bazovsky, Sr., Igor Bazovsky,Jr., George W. Dauncey, Dr. Melvin B. Kline,
Dr. Ernest M. Scheuer, and Dr. David Sternlight participated as co-authors in the
writingofthehandbook; eachcontributedhisparticularexpertiseand practicalexperi
ences.
The individual chapters were written to stand on their own, with a minimum of
cross-referencing between the chapters, so that the reader can concentrate on the
chapters which are of specificinterest to him or to his activity. The interrelations of
maintainabilitywith designengineeringand otherdisciplines(reliability,systemeffec
tiveness,logisticsupport,and lifecyclecosting)arehighlighted throughthewholetext.
Notation and symbols differ in some instances because of the variety of subjects
covered, and in an attempt to be consistent with notation usedin the referenced
standardtexts, documents, and papers pertaining to the varioussubjects.Astandardi
zation of notation is long overdue, as evidenced throughout the maintainability and
reliability Iiterature and also in statistics and probability theory.
The EngineeringDesignHandbooksfallinto two basiccategories-thoseapprovedfor
release and sale, and those classified for security reasons. The US Army Materiel
Command policy is to release these EngineeringDesign Handbooksin accordancewith
current DODDirective7230.7, dated 18September 1973. AllunclassifiedHandbooks
canbe obtainedfromtheNationalTechnicalInformationService(NTIS).Proceduresfor
acquiringtheseHandbooksfollow:
a. All Department of Army activitieshavingneed for the Handbooks must submit
their requestonanofficialrequisitionform(DAForm 17,datedJan70)directlyto:
Commander
Letterkenny ArmyDepot
ATTN: AMXLE-ATD
Chambersburg,PA17201
(Requests for classified documents must be submitted, with appropriate "Need to
Know" justification, to Letterkenny Army Depot.) DA activitieswill not requisition
Handbooksforfurther freedistribution.
xxi
AMCP 706·133
b. All other requestors-DOD, Navy, Air Force, Marine Corps, nonmilitary
Government agencies, contractors, private industry, individuals, universities, and
others-mustpurchasethese Handbooksfrom:
NationalTechnicalInformationService
DepartmentofCommerce
Springfield,VA22151
Classifieddocuments may be released on a "Need to Know"basisverifiedby anofficial
Department ofArmy representative and processed from Defense DocumentationCenter
(DOC), ATTN: DDC·TSR, CameronStation,Alexandria,VA22314.
Comments and suggestions on this Handbook are welcome and should be addressed
to:
Commander
US Army Materiel Development
and Readiness Command
ATTN: DRCRD-TT
Alexandria, VA 22333
(DA Forms 2028, Recommended Changes to Publications, which are available through
normalpublicationssupplychannels, may be used for comments/suggestions.)
xxii
AMCP 706-133
ThisPamphletContainsCopyrighted Material.
DEPARTMENTOFTHE ARMY
HEADQUARTERSUNITEDSTATESARMYMATERIELCOMMAND
5001 EisenhowerAve.,Alexandria, VA22333
AMCPAMPHLET 10 January 1976
No. 706·133
ENGINEERING DESIGN HANDBOOK
MAINTAINABILITY ENGINEERINGTHEORYANDPRACTICE
TABLE OFCONTENTS
Paragraph Page
LISTOFILLUSTRATIONS. . . . . . . . . . . . . . . xv
LISTOFTABLES. . . . . . . . . . . . . . . . . . . . . . xix
PREFACE .. . . . . . . . . . . . . . . . . . . . . . . . . . xxi
CHAPTER 1
THEMAINTAINABILITYCONCEPT
SECTIONI
INTRODUCTION
1-1 General . 1-1
1-2 TheImportanceofMaintainability . 1-4
1-3 PurposeofMaintainability . 1-6
1-4 MaintenanceEngineeringandMaintainability Engi-
neering . 1-7
1-4.1 TheUser-ProducerDialogue . 1-7
1-4.2 MaintenanceEngineering . 1-7
1-4.3 Maintainability Engineering . 1-8
1-4.4 ExamplesofMaintenancePolicyInterrelation-
ships . 1-8
1-5 PrimaryConsiderations . 1-9
SECTIONII
QUANTIFICATIONOFMAINTAINABILITY
1-6 MaintainabilityMeasures . 1-11
1-6.1 TheExponentialCase . 1-11
1-6.2 TheConceptsofMedianRepairTimeandM ' 1-11
MAX
1-6.3 TheRepairRatep. . . . . . . . . . . . . . . . . . . . •. 1-13
1-6.4 TheMeanTimeto Repair(MITR) . 1-13
1-7 SpecificMeasuresinMaintainability. . . . . . . . . . . 1-14
1-7.1 MeasuresofMaintenance Downtime . 1-15
1-7.2 TimeFactorsinMaintenance . 1-18
1-7.3 Availability Factors . 1-20
1-7.4 Maintenance Manhours . 1-20
1-8 StatisticalAspectsandStatisticalDistributions . 1-20
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SECTIONIII
EQUIPMENTCONSIDERATIONSINMAINTAINABILITY
1-9 CategoriesofEquipment . 1-35
1-9.1 Electrical-ElectronicSystems . 1-35
1-9.2 ElectromechanicalSystems . . . . . . . . . . . . 1-36
1-9.3 MechanicalSystems . 1-36
1-9.4 HydraulicandPneumaticSystems . 1-37
1-9.5 OtherSystems . 1-37
1-10 NonreversibleDevices . 1-37
1-11 DesignGuides . 1-38
References . 1-38
CHAPTER2
SYSTEMEFFECTIVENESS
SECTION 1
INTRODUCTION
2-1 General . 2--1
2-2 SystemEffectivenessConcepts . 2-2
2-2.1 TheARINCConceptofSystemEffectiveness . 2--2
2-2.2 TheAirForce(WSEIAC)Concept . 2--3
2-2.3 TheNavyConcept . 2--8
2-2.4 OperationalReadiness,AVailability,andDepend-
ability . 2-8
2-2.4.1 OperationalReadiness . 2-9
2-2.4.2 Availability . 2-9
2-2.4.3 Dependability . 2-9
2-2.5 Performance,Utilization,Capability,andDesign
Adequacy . 2-10
2-2.6 TotalPackagePlanningandSystemEffectiveness. 2--11
2-2.6.1 OperationalStates . 2--11
2-2.6.2 EffectofLogisticSupportonSystemEffec-
tiveness . 2-·14
SECTIONII
SYSTEMEFFECTIVENESSMETHODS
2-3 SystemEffectivenessMeasures . 2-15
2-3.1 TypicalEffectivenessMeasures .. . . . . . . . . . . . 2-15
2-3.2 AssociatedMeasures . 2-16
2-3.2.1 PerformanceMeasures . 2-17
2-3.2.2 ModesofOperation . 2-17
2-3.2.3 ReliabilityMeasures . . . . . . . . . . . . . . . . . . . 2-17
2-3.2.4 MaintainabilityMeasures . . . . . . . . . . . . . . . . 2-17
2-3.2.5 FailureRateConcepts . 2-17
2-4 SystemEffectivenessModels . 2-18
2-4.1 ThePurposeofModels . 2-18
2-4.2 ModelingTechniques . 2-21
ii
2-4.2.1 OperationalReadinessModels.. . . . . . . . . . . . 2-21
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Paragraph Page
2-4.2.2 AvailabilityModels . 2-30
2-4.3 ComplexModels . 2-38
2-4.3.1 TheWSEIACModel . 2-40
2-4.3.2 OtherModels . 2-41
2-5 Trade-OffTechniques . 2-44
2-5.1 General . 2-44
2-5.2 ReliabilityvsMaintainability . 2-44
2-5.3 LinearProgramming . 2-46
2-5.3.1 GeneralFeaturesofaLinearProgramming
ProblemandanExample . 2-48
2-5.3.2 PreliminariestotheSimplexMethod . . . . . 2-52
2-5.3.3 TheSimplexMethod . 2-53
2-5.3.4 OtherLinearProgrammingFormulations . 2-57
2-5.3.5 Maintenance Applications . 2-61
References . 2-61
CHAPTER 3
MAINTAINABILITYORGANIZATIONANDMANAGEMENT
3-1 General . 3-1
3-1.1 OrganizationalActivities . . . . . . . . . . . . . . . . . 3-1
3-1.1.1 MaintainabilityManagementandAdministra-
tion . 3-1
3-1.1.2 Maintainability Analysis . 3-2
3-1.1.3 MaintainabilityDesign . 3-2
3-1.1.4 MaintainabilityDocumentation . 3-2
3-1.1.5 MaintainabilityCoordination . 3-3
3-1.2 OrganizationalStructuresforMaintainability . 3-3
3-1.2.1 Maintainability EngineeringasaCentralized
FunctionalOrganization . 3-3
3-1.2.2 MaintainabilityasaSystemEngineering
StaffFunction . . . . . . . . . . . . . . . . . . . . . . 3-6
3-1.2.3 MaintainabilityinaDecentralizedOrganization . 3-""6
3-2 EffectiveMaintainabilityManagement . 3-9
3-2.1 ManagementFunctionsThroughouttheLife
Cycle . 3-9
3-2.1.1 TheSystemLifeCycle . 3-10
3-2.1.1.1 ConceptDevelopment . 3-10
3-2.1.1.2 ValidationPhase . 3-13
3-2.1.1.3 ProductionPhase . . . . . . . . . . . . . . . . . . . . 3-15
3-2.1.1.4 OperationPhase . 3-15
References . 3-18
CHAPTER4
MAINTAINABILITYALLOCATIONANDPREDICTION
SECTIONI
INTRODUCTION
4-1 General. " . 4-1
4-1.1 MaintainabilityFactors . 4-1
iii
4-1.2 Methodologies . 4-2
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SECfIONII
ALLOCATION
4-2 AllocationFactors . 4-5
4-2.1 BuildingBlockTheoryofAllocation . 4-5
4-2.1.1 System Description . 4-7
4-2.1.1.1 Maintenance FunctionalFlow Block
Diagram . 4-7
4-2.1.1.2 System Functional-LevelBuildingBlock
Diagram . 4-7
4-2.1.1.3 Failure Modes,Effects,andCriticality
Analysis . 4-10
4-2.1.2 AssignmentofMaintainability Factors . 4-10
4-2.1.2.1 System MaintainabilitySynthesis . 4-12
4-2.1.2.2 MaintainabilityImprovementAllocation. . . . . 4-12
4-2.2 CompatibilityofMaintainabilityFactors . 4-13
4-2.3 StatisticalInterdependence . . . . . . . . . . . . . . . 4-13
SECfIONIII
MAINTAINABILITYPREDITION
4-3 General . 4-15
4-4 DevelopmentofaMaintainabilityCriterion . 4-15
4-4.1 BasicAssumptions . . . . . . . . . . . . . . . . . . . . . 4-15
4-4.1.1 Time-to-repairasanIndex . . . . . . . '.' . . . . . . 4-16
4-4.1.2 Time-to-repairCharacteristics . 4-17
4-4.2 PredictionElements . 4-17
4-4.2.1 Failure Rates-ScheduledMaintenanceRates . 4-18
4-4.2.2 Repair Time . 4-19
4-5 PredictionMethods . . . . . . . . . . . . . . . . . . . . . 4-19
4-5.1 ExtrapolationMethods . 4-19
4-5.1.1 PredictionBySmoothing . 4-20
4-5.1.2 PredictionByAssumingDistribution
Characteristics . . . . . . . . . . . . . . . . . . . . . . 4-20
4-5.1.3 NonparametricStatistics . . . . . . . . . . . . . . . . 4-21
4-5.1.4 Estimationofthe DistributionFunction. . . . . . 4-21
4-5.1.5 Estimationofthe PopulationMedian . 4-22
4-5.2 TimeSummationSchemes . 4-26
4-5.3 SimulationMethods . 4-30
4-5.3.1 RandomVariates for Simulations . 4-31
4-5.3.2 ComputerGenerationofRandomVariates . 4-31
4-5.3.3 Example . 4-32
4-5.4 ExpertJudgmentMethod . 4-38
4-5.5 MatrixTabulationMethods . . . . . . . . . . . . . . . 4-39
4-5.5.1 The ARINCSymptomMatrix . 4-39
4-5.5.2 The EPRGSymptom-hypothesisMatrix . 4-39
References . . . . . . . . . . . . . . . . . . . . . •. . . 4-40
iv
AMCP 706·133
TABLEOFCONTENTS (Cont'd)
Paragraph Page
CHAPTERS
MAINTAINABILIlYDESIGNTECHNIQUESANDINTERFACES
SECTIONI
MAINTAINABILIlYDESIGNANDMAINTENANCE
SUPPORTPLANNING
5-1 General . 5-1
5-2 IntegratedLogisticSupportandMaintenance
SupportPlanning . 5-2
5-3 OperationConcept . 5-3
5-4 MaintenanceConcept . 5-4
5-4.1 LevelsofMaintenance . 5-7
5-4.1.1 OrganizationalMaintenance . . . . . . . . . . . . . . 5-7
5-4.1.2 DirectSupportMaintenance . . . . . . . . . . . . . . 5-7
5-4.1.3 GeneralSupportMaintenance . . . . . . . . . . . . . 5-7
5-4.1.4 DepotMaintenance . 5-9
5-4.2 MaintenancePolicies . 5-9
5-5 DevelopmentofMaintainabilityDesign Require-
ments . 5-10
5-5.1 MaintenanceTimePhases . 5-10
5-5.2 CorrectiveMaintenanceDowntime . 5-16
SECTIONII
MAINTAINABILIlYDESIGNCONSIDERATIONS
5-6 MaintainabilityandSystemDesign . . . . . . . . . . . 5-19
5-6.1 InputInforrnation-TheBackgroundforMain
tainabilityDesign . . . . . . . . . . . . . . . . . . . . . 5-21
5-6.2 FormulationoftheValueModel(Effectiveness
Criteria) . 5-21
5-6.3 SynthesisofMaintainabilityDesignModels . 5-21
5-6.4 MaintainabilityAnalysis . . •. . . . . . . . . . 5-21
5-6.5 MaintainabilityEvaluation . 5-22
5-6.6 Decision . 5-22
5-6.7 Optimization. . . . . . . . . . . . . . . . . . . . . . . . . 5-22
5-6.8 OutputInformation . 5-22
5-7 AModelofMaintainabilityDesign . 5-23
5-7.1 MaintainabilityDesignRequirements . 5-23
5-7.2 AnIllustrationofMaintainabilityDesign-
FaultDetection . 5-29
5-7.3 MonitoringasaFaultDetectionTechnique . 5-32
5-8 MaintainabilityDesignCharacteristics .. . . . . . . . 5-34
5-8.1 Checklists . 5-34
5-8.1.1 ChecklistInformationPertainingtoMain-
tenanceDowntimes . 5-37
5-8.1.2 ChecklistsforConsiderationofMaintain-
abilityDesignFactors . 5-37
5-8.2 Packaging . 5-37
5-8.2.1 Accessibility . . . . . . . . . . . . . . . . . . . . . . . . 5-37 v
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5-8.2.2 LogicalFlowPackaging(FunctionalModulari-
zation) . 5-40
5-8.3 StandardizationandInterchangeability . 5-41
5-8.4 HumanFactorsConsiderations . 5-43
5-8.4.1 ManandHisCharacteristicsandCapabilities . . . 5-46
5-8.4.1.1 HumanBodyMeasurement(Anthropometry) 5-46
5-8.4.1.2 Man'sSensoryCapabilityandPsychological
Makeup . 5-46
5-8.4.1.3 ManasanInformationProcessor . . . . . . . . . . 5-47
5-8.4.1.4 Man'sAdaptability . 5-47
5-8.4.2 EnvironmentalConsiderations . 5-47
5-8.4.2.1 Temperature,HUmidity,andAirCirculation .. 5-48
5-8.4.2.2 Illumination . 5-48
5-8.4.2.3 Noise . 5-50
5-8.4.2.4 Vibration . 5-50
5-8.4.2.5 WorkSpaceArrangement . 5-52
5-8.4.3 HumanFactorsElementsinDesigningfor
Maintainability . 5-53
5-8.5 Safety . 5-54
5-8.5.1 SystemSafetyAnalysis . . . . . . . . . . . . . . . . . 5-55
5-8.5.1.1 HazardAnalysis .. . . . . . . . . . . . . . . . . . . . 5-55
5-8.5.1.2 FailureModes,Effects,andCriticality Analysis
(FMECA) . 5-56
5-8.5.1.3 FaultTreeAnalysis , . 5-57
5-8.5.2 SafetyandMaintainabilityDesign . . . . . . . . . . 5-58
5-8.6 TestandCheckout . 5-62
5-8.6.1 ElementsofTestandCheckout . 5-63
5-8.6.2 PurposeandTypeofTests . 5-65
5-8.6.2.1 TestMethods . 5-65
5-8.6.2.2 TypesofTests . 5-67
5-8.6.2.2.1 SystemvsComponentTests . 5-67
5-8.6.2.2.2 StaticvsDynamicTests . 5-67
5-8.6.2.2.3 Open-loopvsClosed-loopTests . 5-68
5-8.6.2.2.4 On-linevsOff-line . 5-68
5-8.6.2.2.5 QuantitativevsQualitative . . . . . . . . . . . . . . 5-68
5-8.6.2.2.6 Oo/no-govsInterpretive . 5-68
5-8.6.3 ClassificationofTestEquipment . 5-68
5-8.6.3.1 MethodofOperation . 5-69
5-8.6.3.2 PointofApplication . . . . . . . . . . . . . . . . . . 5-69
5-8.6.3.3 DesignOrigin .. . . . . . . . . . . . . . . . . . . . . . 5-69
5-8.6.3.4 Versatility . 5-70
5-8.6.3.5 InterfaceWithPrimeEquipment . 5-70
5-8.6.4 AutomaticTestandCheckoutEquipment . 5-71
5-8.6.4.1 Rapidly AdvancingTechnology . 5-71
5-8.6.4.2 BroaderScopeofApplication . . . . . . . . . . . . 5-71
5-8.6.4.3 GreaterEmphasisonEquipmentDegradation.. 5-71
5-8.6.4.4 More Effective Self-testingCapabilities . . . . . . 5-72
5-8.6.4.5 ATEDesignsCompressed/ATEApplication
Broadened . 5-72
vi 5-8.6.4.6 ATECost . 5-72
5-8.6.4.7 StandardizationofATE . 5-72
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5-8.6.4.8 ATEPolicies . 5-73
5-8.6.5 DiagnosticTechniques . 5-73
5-8.6.6 TestandCheckoutDesignConsiderations . 5-74
5-8.6.6.1 TestPhilosophy . 5-74
5-8.6.6.2 TestEquipmentDesignCharacteristics . 5-76
5-8.7 Trade-offs . 5-76
5-8.7.1 Reliability-Maintainability-AvailabilityTrade-off. 5-78
5-8.7.2 TheNSIATrade-offTechnique . 5-83
5-8.7.3 Repair/DiscardTrade-offDecisions . 5-86
5-8.7.3.1 Repair/DiscardModels . 5-93
5-8.7.3.2 ImpactofRepair/DiscardDecisionson
Maintainability. . . . . . . . . . . . . . . . . . . . . . 5-95
5-8.8 CostConsiderations . . . . . . .. . . . . . . . . . . . . . 5-97
References . . •. . . . . ••. . . . . •. . . ••. . •••• 5-98
CHAPTER6
MAINTAINABILITYTESTANDDEMONSTRATION
SECTIONI
INTRODUCTION
6-1 GeneralRequirements . 6-1
6-1.1 PlanningandControlRequirements . 6-2
6-2 TestApproaches . 6-6
6-2.1 TypesofTestApproaches . 6-10
6-2.2 User-ServiceTests . 6-12
6-2.3 TaskSelection . 6-13
SECTIONII
METHODSOFTESTING
6-3 TestTechniques . 6-15
6-4 SamplingandSampleSizeSelection . . . . . 6-16
6-4.1 StatisticalMethodsinSampleSelection . . . . . . . 6-16
6-5 ReductionofTesting . 6-25
6-6 DemonstrationData . 6-25
6-6.1 CollectionofDemonstrationData. . . . . . . . . . . 6-25
6-6.2 Reporting,Storage,andRecoveryof
DemonstrationData . 6-26
6-7 DemonstrationMethods . 6-26
6-7.1 SequentialTestPlans .. . . . . . . . . . . . . . . . . . 6-27
6-7.2 TestPlansBasedontheCentralLimitTheorem .. 6-27
6-7.2.1 TestsinMIL-STD-471 . 6-32
6-7.2.2 TheTestofMIL-STD-473 . 6-35
6-7.3 EquipmentRepairTime(ERT)Techniques . 6-36
6-7.4 TechniqueswhenUnderlyingDistributionsof
DataareUnknown . 6-37
6-7.4.1 ProcedureofMIL-STD-473 . 6-37
6-7.4.2 ProceduresofMIL-STD-471 . 6-38
6-7.5 Goodness-of-FitTechniques .. . . . . . . . . . . . . . 6-41
6-7.5.1 Chi-squareProcedures . 6-41 vii
6-7.5.2 ExponentialDistribution . . . . . . . . . . . . . . . . 6-42