Statisticalmethodsin guality management武汉理工大学机电工程学院工业工程系李存荣（cunrongli@163.com）Statistical methods commonly used2007.4for quality management
2007.4 1 Statistical methods in quality management Statistical methods commonly used for quality management 武汉理工大学 机电工程学院 工业工程系 李存荣（cunrong_li@163.com）
"Quality management" is to direct and controlthe activities that related to the qualityo Quality is aset of inherent characteristics that meet therequirementsoQuality management experience in three phases:the quality inspection, statistical quality control,comprehensivequalitymanagement2007.4Statistical techniques2
2007.4 2 Statistical techniques “Quality management” is to direct and control the activities that related to the quality. Quality is a set of inherent characteristics that meet the requirements. Quality management experience in three phases: the quality inspection, statistical quality control, comprehensive quality management
The quality inspection phase:Support theory :Taylor's"scientific management"Advantage:separate the production and inspection ;avoid the unqualified products flow into the market ;Disadvantage:Even find the unqualified products, the loss hasoccurred andcannotberedeemed:Quality is the result of the inspection2007.4Statistical techniques3
2007.4 3 Statistical techniques The quality inspection phase: Support theory ：Taylor's "scientific management“. Advantage ： separate the production and inspection ； avoid the unqualified products flow into the market ； Disadvantage ： Even find the unqualified products, the loss has occurred and cannot be redeemed; Quality is the result of the inspection
statistical guality control phase:Support theory: Statistical inference theoryThe founder : Hart, dodge and RomigQKZAdvantage:5M1Eprocesschange the “later check" of the pure quality inspectionto the “prevention and control"Disadvantage : Excessively emphasized the study ofmathematical statistics theory;Mainly used in the manufacturing stage2007.4Statistical techniques4
2007.4 4 Statistical techniques statistical quality control phase: Support theory: Statistical inference theory The founder ：Hart, dodge and Romig Advantage ： 5M1E process QKZ change the “later check” of the pure quality inspection to the “prevention and control”; Disadvantage ： Excessively emphasized the study of mathematical statistics theory; Mainly used in the manufacturing stage
5MIEMachine The machine aging, new machine.MaterialReplacement of suppliers replacement of materials,The change of material mechanical or chemical properties, the changeof materials' size.MethodThe change of processThe change of operating stationmethod、Impropertoolfixture.Operatorthe degree of proficiency of operator, the habituation ofoperator,Did the operator operate in accordance with the operationstandard,the physical power and emotion of operator, operator'sworkplace and toolsMeasurement Measurement technique accuracyof measuringinstrumentsEnvironmental factorsThe stability of sourceThe stability of water quality、Temperature,humidity、The air dust、illuminance clean the floor and work places set out the items of2007.4workplace5
2007.4 5 5M1E • Machine The machine aging , new machine. • Material Replacement of suppliers 、 replacement of materials、 The change of material mechanical or chemical properties 、the change of materials’ size. • Method The change of process 、 The change of operating station method 、 Improper tool fixture . • Operator the degree of proficiency of operator, the habituation of operator , Did the operator operate in accordance with the operation standard , the physical power and emotion of operator , operator's workplace and tools • Measurement Measurement technique 、accuracy of measuring instruments • Environmental factorsThe stability of source The stability of water quality 、 Temperature, humidity 、 The air dust 、 illuminance 、 clean the floor and work places 、 set out the items of workplace