Introduction to Statistical Quality Control, 4th Edition

1、Introduction to Statistical Quality Control, 4th EditionDouglas C. MontgomeryArizona State UniversityChapter 1Quality Improvement in the Modern Business Environment1-1. The Meaning of Quality and Quality Improvement1-1.1 Dimensions of Quality1-1.2 Quality Engineering Technology1-1.1 Dimensions of Qu

2、alityPerformanceReliabilityDurabilityServiceabilityAestheticsFeaturesPerceived QualityConformance to standards1-1.1 Dimensions of QualityDefinitions of Quality Quality means fitness for use - quality of design - quality of conformance Quality is inversely proportional to variability.1-1.1 Dimensions

3、 of QualityQuality Improvement Quality improvement is the reduction of variability in processes and products. Alternatively, quality improvement is also seen as “waste reduction.1-1.1 Dimensions of Quality Transmission Example 1-1.2 Quality Engineering TerminologyQuality CharacteristicsPhysical - le

4、ngth, weight, voltage, viscositySensory - taste, appearance, colorTime Orientation - reliability, durability, serviceability1-1.2 Quality Engineering TerminologyQuality engineering is the set of operational, managerial, and engineering activities that a company uses to ensure that the quality charac

5、teristics of a product are at the nominal or required levels.1-1.2 Quality Engineering TerminologyTwo types of dataAttributes Data - discrete data, often in the form of counts.Variables Data - continuous measurements such as length, weight.1-1.2 Quality Engineering TerminologySpecifications Quality

6、characteristics being measured are often compared to standards or specifications.Nominal or target valueUpper Specification Limit (USL)Lower Specification Limit (LSL)1-1.2 Quality Engineering TerminologyWhen a component or product does not meet specifications, they are considered to be nonconforming

7、.A nonconforming product is considered defective if it has one or more defects.Defects are nonconformities that may seriously affect the safe or effective use of the product.1-1.2 Quality Engineering TerminologyConcurrent EngineeringTeam approach to design. Specialists from manufacturing, quality en

8、gineering, management, etc. work together for product or process improvement.1-2. A Brief History of Quality Control and Improvement(Refer to Table 1-1)Walter Shewhart (1924) introduced statistical control chart concepts.The American Society for Quality Control formed in 1946 (now known as the Ameri

9、can Society for Quality (ASQ).1950s and 1960s saw an increase in reliability engineering, experimental design, and statistical quality control1-2. A Brief History of Quality Control and Improvement(Refer to Table 1-1)Competition from foreign industries (Japan) increases during the 1970s and 1980s.St

10、atistical methods for quality improvement use increases in the United States during the 1980sTotal Quality Management (TQM) emerges during 1970s and into the 1980s as an important management tool to implement statistical methods.1-2. A Brief History of Quality Control and ImprovementMalcolm Baldridg

11、e National Quality Award is established in 1988.ISO 9000 certification activities increase in U.S. industry in the 1990s.Motorolas Six-Sigma initiative begins in the 1990s.1-3. Statistical Methods for Quality Control and ImprovementThree major areas:Statistical process control (SPC)Design of experim

12、ents (DOX)Acceptance sampling1-3. Statistical Methods for Quality Control and ImprovementStatistical ProcessControl (SPC)Control charts are used for process monitoring and variability reduction.SPC is an on-line quality control tool.1-3. Statistical Methods for Quality Control and ImprovementDesign

13、of ExperimentsExperimental design is an approach to systematically varying the controllable input factors in the process and determine the effect these factors have on the output responses.Experimental designs are off-line quality tools.Crucial for variability reduction.1-3. Statistical Methods for

14、Quality Control and ImprovementAcceptance SamplingAcceptance sampling is the inspection and classification of a sample of the product selected at random from a larger batch or lot and the ultimate decision about disposition of the lot.Two types:1. Outgoing inspection - follows production2. Incoming

15、inspection - before use in production1-4. Other Aspects of Quality Control and ImprovementTotal Quality Management (TQM)TQM is a managerial framework to accomplish quality improvement.Other names and related approaches:Company-Wide Quality Control (CWQC)Total Quality Assurance (TQA)Six-Sigma1-4. Oth

16、er Aspects of Quality Control and Improvement1-4.1 Quality Philosophy and Management Strategies1-4.2 The Link Between Quality and Productivity1-4.3 Quality Costs1-4.4 Legal Aspects of Quality1-4.5 Implementing Quality Improvement1-4.1 Quality Philosophy and Management StrategiesThree Important Leade

17、rsW. Edwards Deming- Emphasis on statistical methods in quality improvement (see Demings 14 points)Joseph Juran- Emphasis on managerial role in quality implementationArmand V. Feigenbaum- Emphasis on organizational structure 1-4.1 Quality Philosophy and Management StrategiesTotal Quality Management

18、(TQM)Quality Standards and RegistrationISO 9000Six SigmaJust-In-Time, Lean Manufacturing, Poka-Yoke, etc.1-4.2 The Link Between Quality and ProductivityEffective quality improvement can be instrumental in increasing productivity and reducing cost.The cost of achieving quality improvements and increased productivity is often negligible.1-4.3 Quality CostsQuality Costs are those categories of costs that are associated with producing, identifying, avoiding, or repairin