Reliability And Cost Impacts For Attritable Systems
Air Force Institute of TechnologyAFIT ScholarTheses and Dissertations3-23-2017Reliability and Cost Impacts for Attritable SystemsBryan R. BentzFollow this and additional works at: https://scholar.afit.edu/etdPart of the Systems Engineering CommonsRecommended CitationBentz, Bryan R., "Reliability and Cost Impacts for Attritable Systems" (2017). Theses and Dissertations. 806.https://scholar.afit.edu/etd/806This Thesis is brought to you for free and open access by AFIT Scholar. It has been accepted for inclusion in Theses and Dissertations by an authorizedadministrator of AFIT Scholar. For more information, please contact richard.mansfield@afit.edu.
RELIABILITY AND COST IMPACTS FOR ATTRITABLE SYSTEMSTHESISBryan R. Bentz, 1st Lieutenant, USAFAFIT-ENV-MS-17-M-172DEPARTMENT OF THE AIR FORCEAIR UNIVERSITYAIR FORCE INSTITUTE OF TECHNOLOGYWright-Patterson Air Force Base, OhioDISTRIBUTION STATEMENT AAPPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED.
The views expressed in this thesis are those of the author and do not reflect the officialpolicy or position of the United States Air Force, Department of Defense, or the U.S.Government. This material is declared a work of the U.S. Government and is not subjectto copyright protection in the United States.
AFIT-ENV-MS-17-M-172RELIABILITY AND COST IMPACTS FOR ATTRITABLE SYSTEMSTHESISPresented to the FacultyDepartment of Systems Engineering and ManagementGraduate School of Engineering and ManagementAir Force Institute of TechnologyAir UniversityAir Education and Training CommandIn Partial Fulfillment of the Requirements for theDegree of Master of Science in Systems EngineeringBryan R. Bentz, BS1st Lieutenant, USAFMarch 2017DISTRIBUTION STATEMENT AAPPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED
AFIT-ENV-MS-17-M-172RELIABILITY AND COST IMPACTS FOR ATTRITABLE SYSTEMSBryan R. Bentz, BS1st Lieutenant, USAFCommittee Membership:John M. Colombi, Ph.D.ChairJason K. Freels, Maj, USAF, Ph.D.MemberJason W. Sutherlin, Capt, USAF (Member)Member
AcknowledgmentsMany thanks to my faculty advisor, Dr. Colombi, for his willingness to supportmy research of this rich area of study. Without his guidance and candor, I would nothave been able to complete this thesis effort. Thanks to my sponsor at AFRL/RQVI fortreating the academic support as valuable members of the team. Additionally, thanks areowed to my contact the engineers at the Subscale Aerial Targets branch, without whommy quest for “attritable” field data would have come to naught. And finally, to my wife –without your supreme patience I may not have finished at all.Bryan R. Bentzvi
Table of ContentsAcknowledgments. viList of Figures .xList of Tables . xiiiList of Acronyms . xivAbstract .xv1.0 Reliability and Cost Impacts for an Attritable System .11.1Chapter Overview .11.2Background .11.3Definitions .61.4Research Objectives .81.5Investigative Questions .81.6Methodology Overview.81.7Assumptions and Limitations .101.8Research Preview .122.0 Review of Literature for Relating to Attritability, Reliability and Cost .132.1Chapter Overview .132.2The Characteristic of Attritability .132.3System Reliability Engineering.152.3.1Contexts of System Reliability. 172.3.2 Reliability Metrics . 192.3.3 Reliability Models . 262.3.4 Reliability Model Development . 32vii
2.4Cost Estimation and Cost Risk .342.5 Competing Risks Analysis .372.6Gap Analysis .383.0 Methodology to Trade Attritable System Reliability and Cost .403.1 Chapter Overview .403.2 Assumptions .413.3 Data and Materials .453.4 Processes and Procedures .504.0 Data Analysis and Results .574.1Chapter Overview .574.2Suitability of the Markov Chain Technique .584.3Reliability Model Results .674.3.1Hazard Rate Variation . 684.3.2Reparability Variation . 724.4Cost Risk Estimation .754.5 Conclusions .825.0 Conclusions and Recommendations .865.1Chapter Overview .865.2Investigative Question Review .865.2.1 Metrics and Methods Suitable for Attritable System Reliability . 865.2.2Sensitivities to Variations of Reliability and Reparability. 885.2.3 Consequences of Trading Reliability and Reparability on Cost Risk . 895.3Recommendations for Future Research .90viii
5.4Significance of Research.92Bibliography .94Vita .99Appendix A: Data Analysis in R .100Appendix B: IEEE SysCon 2017 Conference Paper .168ix
List of FiguresPageFigure 1: Illustrative System Lifecycle (Source: CAPE, 2014, 2-1) . 4Figure 2: Commitment, system-specific knowledge and cost (Source: Blanchard &Fabrycky, 1998, Figure 2.11) . 5Figure 3: Costs associated with a reactive reliability program (Source: Yang, 2007, p. 47). 17Figure 4: The Four Context Areas of Reliability Analysis (Source: Hogge, 2012, p. 11) 18Figure 5: Heirarchy of MFOP Options (Source: Relf, 1999, 112) . 22Figure 6: Bathtub Curve for Hardware Reliability (Source: Pan, 1999) . 25Figure 7: Markov Modeling Process (Source: RAC, 2003) . 33Figure 8: Operational dependability model construction process (Source: Tiassou, 2013). 34Figure 9: Cost Estimating Methodology (Source: DAU) . 35Figure 10: Attritable Air Vehicle UML Object Diagram (Note: System representationexcludes mission payload) . 43Figure 11: Methodology for the Study of Reliability and Cost Trades for AttritableSystems . 51Figure 12: Example Markov Chain Model with Identified Subsystems. 52Figure 13: Cumulative Incidence Function (CIF) of Subsystem Failure Modes . 59Figure 15: Hazard Rate of Electronics Subsystem . 60Figure 14: Hazard Rate of Fuel Mgmt Subsystem. 60x
Figure 16: Hazard Rate of Operator. 60Figure 17: Hazard Rate of Launcher Subsystem . 60Figure 18: Hazard Rate of Recovery Subsystem . 61Figure 19: Hazard Rate of Propulsion Subsystem . 61Figure 20: Hazard Rate of Structural Subsystem . 61Figure 21: Fuel Mgmt CIF vs. Exponential Q-Q Plot . 62Figure 22: Electronics CIF vs. Exponential Q-Q Plot . 62Figure 23: Operator CIF vs. Exponential Q-Q Plot . 63Figure 24: Launcher CIF vs. Exponential Q-Q Plot . 63Figure 25: Recovery CIF vs. Exponential Q-Q Plot . 63Figure 26: Propulsion CIF vs. Exponential Q-Q Plot . 63Figure 27: Structure CIF vs. Exponential Q-Q Plot. 63Figure 28: Baseline System Survival Function. 68Figure 29: S(n) with Altered Fuel Mgmt Subsystem . 69Figure 30: S(n) with Altered Electronics Subsystem . 69Figure 31: S(n) with Altered Operator . 69Figure 32: S(n) with Altered Launcher Subsystem. 69Figure 33: S(n) with Altered Recovery Subsystem . 70Figure 34: S(n) with Altered Propulsion Subsystem . 70Figure 35: S(n) with Altered Structure . 70Figure 36: Sensitivity of Trading Subsystem hazard Rate on Survival Function . 71Figure 37: System Survival Function without Propulsion Subsystem Repair . 73xi
Figure 38: System Survival Function without Structural Repair . 74Figure 39: Absolute System Cost Risk of the Baseline Attritable Air Vehicle . 76Figure 40: Absolute Cost Risk per Sortie for Non-Repairable Propulsion Subsystem . 77Figure 41: Absolute System Cost Risk per Sortie for a Non-Repairable Structure . 77Figure 42: Equivalent Cost Risk for a Trade in Electronics Hazard Rate . 80Figure 43: Equivalent Cost Risk for a Trade in Propulsion Hazard Rate . 81Figure 44: Attritable and Survival Design Spaces based on Equivalent Cost Risk . 85xii
List of TablesTable 1: Baseline System Failure-time Data . 49Table 2: Direction of Subsystem Hazard Rate Variation and Justification . 53Table 3: Alteration of Subsystem Reparability and Justification . 54Table 4: Example Cost Values Used in Cost Risk Estimation . 55Table 5: Comparison of AICc for Exponential and Weibull Distributions . 65Table 6: Estimated MTBF of Seven Subsystems . 168xiii
List of DR&DRACRBDROCOFRPARQKPSANSEBoKUASUAVUMLAdvanced Concept Technology DemonstratorAir Force Research LaboratoryAdvisory Group on the Reliability of Electronics EngineersAverage Unit Flyaway CostCost Assessment and Program EvaluationCost Estimation RelationshipCumulative Incidence FunctionDefense Acquisition UniversityDepartment of DefenseDepartment of Defense InstructiveDefense Operational Test and EvaluationFault Tree AnalysisHeadquarters, Air ForceIntelligence, Surveillance, and ReconaissanceJoint Program OfficeKaplan-Meier EstimatorLow Cost Attritable Aircraft TechnologyMedium Altitude, Long EnduranceMean Cumulative FunctionMarkov Chain Monte CarloMaintenance Free Operating PeriodMean Time between FailuresMean Time to FailureNon-Developmental ItemOperations and SupportOffice of the Secretary of DefenseResearch and DevelopmentReliability Analysis CenterReliability Block DiagramRate of Occurrence of FailureRemotely Piloted AircraftOffice Symbol of the Air Vehicle Directorate’s contracting branchStochastic Activity NetworkSystems Engineering Body of KnowledgeUnmanned Aerial SystemUnmanned Aerial VehicleUnified Modeling Languagexiv
AFIT/GSE/ENV/17--172AbstractAttritable systems trade system attributes like reliability and reparability toachieve lower acquisition cost and decrease cost risk. Ultimately, it is hoped that bytrading these attributes the amount of systems able to be acquired will be increased.However, the effect of trading these attributes on system-level reliability and cost risk isdifficult to express complicated reparable systems like an air vehicle. Failure-time andcost data from a baseline limited-life air vehicle is analyzed for this reliability andreparability trade study. The appropriateness of various reliability and cost estimationtechniques are examined for these data. This research employs the cumulative incidencefunction as an input to discrete time non-homogeneous Markov chain models toovercome the hurdles of representing the failure-time data of a reparable system withcompeting failure modes that vary with time. This research quantifies the probability ofsystem survival to a given sortie,, average unit flyaway cost (AUFC), and cost riskmetrics to convey the value of reliability and reparability trades. Investigation of thebenefit of trading system reparability shows a marked increase in cost risk. Yet, trades insubsystem reliability calculate the required decrease in subsystem cost required to makesuch a trade advantageous. This research results in a trade-space analysis tool that can beused to guide the development of future attritable air vehicles.xv
1.11.0Reliability and Cost Impacts for an Attritable SystemChapter OverviewThis introductory chapter establishes a definition for the term “attritable” foundedon recent research activities within the context of a limited-life air vehicle and examinesthe system attributes of design life and reliability. These definitions are used to formulatethe fundamental problem statement and the related investigate questions that must beanswered within this research. The methodology by which these investigative questionswill be addressed is outlined, yet covered in detail in proceeding chapters. Finally, thesimplifying assumptions that this reliability and cost research is predicated upon areexamined. The limitations that data availability and the choice of modeling techniqueimpose on the research outcomes are also discussed.1.2BackgroundIn 2014, the Secretary of Defense at the time introduced the “third offset strategy”to a group of defense experts at the Reagan Defense Forum. The third offset seeks tobuild off of the strategies emphasized in the first and second offsets of the 1950s andmid-1970s, respectively to ensure the United States could overcome a loomingquantitative disadvantage in future conflicts. The third offset strategy’s intent is to buildoff of earlier accomplishments in nuclear deterrence, intelligence, surveillance andreconnaissance (ISR), precision weapons, stealth, and space-based militarycommunication and navigation through improving the performance and decision-makingability of the warfighter in highly-contested environments.1
Deputy Secretary of Defense Bob Work (2014 – Present) identified the five pillarsof the Third Offset strategy, which he highlighted will be “looked favorably upon in thebudget,” when he addressed the Center for New American Security in 2015. The fivepillars include: support of technologies to improve learning systems, human-machinecollaboration, combat teaming, assisted human operations, and cyber-hardened yetnetwork-enabled autonomous weapons (Mehta, 2015). Yet, Work specifically challengeddevelopers of autonomous aircraft in his address. Work ventured, “What we want to doon human-machine combat teaming is to take it to the next level, to look at things likeswarming tactics. Can an F-35 go into battle with four unmanned wingmen?” (Mehta,2015).Air Force guidelines, such as Headquarters, Air, Force’s (HAF) USAF FutureOperating Concept and the Remotely Piloted Aircraft (RPA) Vector Vision EnablingConcepts 2013-2038 align with the course plotted by DoD leadership. In this guideline itis acknowledged that the next generation of autonomous aircraft that “must detect, avoid,or counter known threats via traditional or innovative means, to enable operations in arange of environments” (HAF, 2014, p. 32) HAF states that, “this can be achievedthrough a combination of speed, low observable technology, altitude, maneuverability,employment of air-launched Small Unmanned Aerial Systems, active and passivecountermeasures, or expendable assets.” (HAF, 2014, p.32
Attritable systems trade system attributes like reliability and reparability to achieve lower acquisition cost and decrease cost risk. Ultimately, it is hoped that by trading these attributes the amount of systems able to be acquired will be increased. However, the effect of trading these attributes on system-level reliability and cost risk is
Bruksanvisning för bilstereo . Bruksanvisning for bilstereo . Instrukcja obsługi samochodowego odtwarzacza stereo . Operating Instructions for Car Stereo . 610-104 . SV . Bruksanvisning i original
10 tips och tricks för att lyckas med ert sap-projekt 20 SAPSANYTT 2/2015 De flesta projektledare känner säkert till Cobb’s paradox. Martin Cobb verkade som CIO för sekretariatet för Treasury Board of Canada 1995 då han ställde frågan
service i Norge och Finland drivs inom ramen för ett enskilt företag (NRK. 1 och Yleisradio), fin ns det i Sverige tre: Ett för tv (Sveriges Television , SVT ), ett för radio (Sveriges Radio , SR ) och ett för utbildnings program (Sveriges Utbildningsradio, UR, vilket till följd av sin begränsade storlek inte återfinns bland de 25 största
Hotell För hotell anges de tre klasserna A/B, C och D. Det betyder att den "normala" standarden C är acceptabel men att motiven för en högre standard är starka. Ljudklass C motsvarar de tidigare normkraven för hotell, ljudklass A/B motsvarar kraven för moderna hotell med hög standard och ljudklass D kan användas vid
LÄS NOGGRANT FÖLJANDE VILLKOR FÖR APPLE DEVELOPER PROGRAM LICENCE . Apple Developer Program License Agreement Syfte Du vill använda Apple-mjukvara (enligt definitionen nedan) för att utveckla en eller flera Applikationer (enligt definitionen nedan) för Apple-märkta produkter. . Applikationer som utvecklas för iOS-produkter, Apple .
Test-Retest Reliability Alternate Form Reliability Criterion-Referenced Reliability Inter-rater reliability 4. Reliability of Composite Scores Reliability of Sum of Scores Reliability of Difference Scores Reliability
This presentation and SAP's strategy and possible future developments are subject to change and may be changed by SAP at any time for any reason without notice. This document is 7 provided without a warranty of any kind, either express or implied, including but not limited to, the implied warranties of merchantability, fitness for a .
och krav. Maskinerna skriver ut upp till fyra tum breda etiketter med direkt termoteknik och termotransferteknik och är lämpliga för en lång rad användningsområden på vertikala marknader. TD-seriens professionella etikettskrivare för . skrivbordet. Brothers nya avancerade 4-tums etikettskrivare för skrivbordet är effektiva och enkla att
