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1、Reliability and Quality ControlESE 405/505Professor Paul S.MinChapter 1.Quality Improvement in the Modern Business EnvironmentEight Dimensions of Quality1.Performance2.Reliability3.Durability4.Serviceability5.Aesthetics6.Features7.Perceived Quality8.Conformance to Standards Quality:traditionally,fit
2、ness for use-Quality of design-Quality of conformance-Inversely proportional to variability(modern concept)Quality Improvement:Reduction of variability in processes and products(or elimination of waste)Critical-to-Quality Characteristics(CTQ)Physical:length,weight,voltage,viscosity Sensory:taste,app
3、earance,color Time Orientation:reliability,durability,ServiceabilitySpecificationsLower specification limitUpper specification limitTarget or nominal valuesDefect versus nonconformity:not all products containing a defect are necessarily defectiveHistory of Quality ImprovementStatistical MethodsStati
4、stical process control(SPC)Control charts,plus other problem-solving toolsUseful in monitoring processes,reducing variability through elimination of assignable causesOn-line techniqueDesigned experiments(DOX)Discovering the key factors that influence process performanceProcess optimizationOff-line t
5、echniqueAcceptance SamplingWalter A.Shewart (1891-1967)Trained in engineering and physics Long career at Bell Labs Developed the first control chart about 1924A factorial experiment with three factorsEffective management of quality requires the execution of three activities:1.Quality Planning2.Quali
6、ty Assurance3.Quality Control and ImprovementQuality Philosophies and Management StrategiesW.Edwards DemingTaught engineering,physics in the 1920s,finished PhD in 1928Met Walter Shewhart at Western ElectricLong career in government statistics,USDA,Bureau of the CensusDuring WWII,he worked with US de
7、fense contractors,deploying statistical methodsSent to Japan after WWII to work on the censusDemingDeming was asked by JUSE to lecture on statistical quality control to managementJapanese adopted many aspects of Demings management philosophyDeming stressed“continual never-ending improvement”Deming l
8、ectured widely in North America during the 1980s;he died 24 December 1993Demings 14 Points1.Create constancy of purpose toward improvement 2.Adopt a new philosophy,recognize that we are in a time of change,a new economic age3.Cease reliance on mass inspection to improve quality4.End the practice of
9、awarding business on the basis of price alone5.Improve constantly and forever the system of production and service6.Institute training7.Improve leadership,recognize that the aim of supervision is help people and equipment to do a better job8.Drive out fear9.Break down barriers between departments14
10、Points continued10.Eliminate slogans and targets for the workforce such as zero defects11.Eliminate work standards12.Remove barriers that rob workers of the right to pride in the quality of their work13.Institute a vigorous program of education and self-improvement14.Put everyone to work to accompli
11、sh the transformationNote that the 14 points are about changeDemings Deadly Diseases1.Lack of constancy of purpose2.Emphasis on short-term profits3.Performance evaluation,merit rating,annual reviews4.Mobility of management5.Running a company on visible figures alone6.Excessive medical costs for empl
12、oyee health care7.Excessive costs of warranteesJoseph M.JuranBorn in Romania(1904),immigrated to the USWorked at Western Electric,influenced by Walter ShewhartEmphasizes a more strategic and planning oriented approach to quality than does DemingJuran Institute is still an active organization promoti
13、ng the Juran philosophy and quality improvement practicesThe Juran Trilogy1.Planning2.Control3.ImprovementThese three processes are interrelatedControl versus breakthroughProject-by-project improvementKaoru IshikawaSon of the founder of JUSE,promoted widespread use of basic toolsArmand FeigenbaumAut
14、hor of Total Quality Control,promoted overall organizational involvement in qualityThree-step approach emphasized quality leadership,quality technology,and organizational commitment Total Quality Management(TQM)Started in the early 1980s,Deming/Juran philosophy as the focal pointEmphasis on widespre
15、ad training,quality awarenessTraining often turned over to HR functionNot enough emphasis on quality control and improvement tools,poor follow-through,no project-by-project implementation strategyTQM was largely unsuccessfulQuality Systems and StandardsInternational Standard Organization(ISO)in 1987
16、ISO 9000:2000 Quality Management System Fundamentals and VocabularyISO 9001:2000 Quality Management System RequirementsISO 9004:2000 Quality Management System Guidelines for Performance ImprovementA company can be certified by selecting a registrar and receiving a certification audit.Once certified,
17、the company also receives periodic surveillance audits.Six SigmaUse of statistics&other analytical tools has grown steadily for over 80 years Statistical quality control(origins in 1920,explosive growth during WW II,1950s)Operations research(1940s)FDA,EPA in the 1970sTQM(Total Quality Management)mov
18、ement in the 1980sReengineering of business processes(late 1980s)Six-Sigma(origins at Motorola in 1987,expanded impact during 1990s to present)Focus of Six Sigma is on Process Improvement with an Emphasis on Achieving Significant Business ImpactA process is an organized sequence of activities that p
19、roduces an output that adds value to the organizationAll work is performed in(interconnected)processesEasy to see in some situations(manufacturing)Harder in othersAny process can be improvedAn organized approach to improvement is necessaryThe process focus is essential to Six SigmaWhy“Quality Improv
20、ement”is Important:A Simple Example A visit to a fast-food store:Hamburger(bun,meat,special sauce,cheese,pickle,onion,lettuce,tomato),fries,and drink.This product has 10 components-is 99%good okay?Six Sigma FocusInitially in manufacturing Commercial applicationsBankingFinancePublic sector ServicesDF
21、SS Design for Six SigmaOnly so much improvement can be wrung out of an existing systemNew process designNew product design(engineering)Some Commercial ApplicationsReducing average and variation of days outstanding on accounts receivableManaging costs of consultants(public accountants,lawyers)Skip tr
22、acingCredit scoringClosing the books(faster,less variation)Audit accuracy,account reconciliation ForecastingInventory managementTax filingPayroll accuracySix SigmaA disciplined and analytical approach to process and product improvementSpecialized roles for people;Champions,Master Black belts,Black B
23、elts,Green BeltsTop-down driven(Champions from each business)BBs and MBBs have responsibility(project definition,leadership,training/mentoring,team facilitation)Involves a five-step process(DMAIC):Define MeasureAnalyzeImproveControlWhat Makes it Work?Successful implementations characterized by:Commi
24、tted leadershipUse of top talentSupporting infrastructureFormal project selection processFormal project review processDedicated resourcesFinancial system integrationProject-by-project improvement strategy(borrowed from Juran)LEANVariation ReductionPredictabilityFeasibilityEfficiencyCapabilityAccurac
25、yFlow Mapping Waste EliminationCycle TimeWIP ReductionOperations and Design LeanDMAICELIMINATE WASTE,IMPROVE CYCLE TIMEDESIGN PREDICTIVE QUALITY INTO PRODUCTSELIMINATE DEFECTS,REDUCE VARIABILITYDFSSRequirements allocationCapability assessmentRobust DesignPredictable Product QualityDesign for Six Sig
26、maProcess Improvement TriadDFSS Matches Customer Needswith CapabilityMean and variability affects product performance and costDesigners can predict costs and yields in the design phaseConsider mean and variability in the design phaseEstablish top level mean,variability and failure rate targets fora
27、designRationally allocate mean,variability,and failure rate targets to subsystem and component levelsMatch requirements against process capability and identify gaps Close gaps to optimize a producible designIdentify variability drivers and optimize designs or make designs robust to variabilityProces
28、s capability impact design decisionsLean Focuses on Waste EliminationDefinition:A set of methods and tools used to eliminate waste in a processLean helps identify anything not absolutely required to deliver a quality product on time.Benefits of using LeanLean methods help reduce inventory,lead time,
29、and costLean methods increase productivity,quality,on time delivery,capacity,and salesDMAIC Solves Problems by UsingSix Sigma Tools DMAIC is a problem solving methodologyUse this method to solve problems:Define problems in processesMeasure performanceAnalyze causes of problemsImprove processesremove
30、 variations and nonvalue-added activitiesControl processes so problems do not recurSix SigmaDMAIC is closely related to the Shewhart cycleQuality CostsLegal Aspects of QualityProduct liability exposureConcept of strict liability1.Responsibility of both manufacturer and seller/distributor2.Advertisin
31、g must be supported by valid data A strategic management process,focused along the eight dimensions of quality Suppliers and supply chain management must be involved Must focus on all three components:Quality Planning,Quality Assurance,and Quality Control and ImprovementImplementing Quality Improvement