Lecture Fundamentals of operations management (4/e): Chapter 9 - Davis, Aquilano, Chase

Chapter 6 Quality control tools for improving processes, after studying this chapter you will be able to: Introduce the different quality control tools that are used in analyzing and improving the quality of processes, describe in detail the two major approaches (that is, acceptance sampling and statistical process control) in which statistical analysis can be used to improve process quality, define the two different types of errors that can occur when statistical sampling is used,...

DAVIS F   O   U   R   T   H       E   D   I   T   I   O   N AQUILANO CHASE supplement Quality Control Tools for  Improving Processes © The McGraw-Hill Companies, Inc., 2003 PowerPoint Presentation by Charlie Cook Supplement Objectives Supplement Objectives • Introduce the different quality control tools that are used in analyzing and improving the quality of processes • Describe in detail the two major approaches (that is, acceptance sampling and statistical process control) in which statistical analysis can be used to improve process quality • Define the two different types of errors that can occur when statistical sampling is used ã Distinguish between attributes and variables with âTheMcGrawưHill respect to the statistical analysis of processes Fundamentals of Operations  Companies, Inc., 2003 Management 4e  S6–2 Supplement Objectives (cont’d) Supplement Objectives (cont’d) • Discuss Taguchi methods and how they are different from traditional statistical quality control methods • Describe the quantitative methodology behind six sigma Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 S6–3 The Basic Quality Control Tools The Basic Quality Control Tools • Seven Basic Quality Control (QC) Tools –Process flowcharts (or diagrams) –Bar charts and histograms –Pareto charts –Scatterplots (or diagrams) –Run (or trend) charts –Cause-and-effect (or fishbone) charts –Statistical process control Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 S6–4 Checksheet for Recording Complaints Checksheet for Recording Complaints Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.1 S6–5 Checksheet for Group Sizes in a Restaurant Checksheet for Group Sizes in a Restaurant Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.2 S6–6 Bar Chart of Daily Units Produced Bar Chart of Daily Units Produced Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.3 S6–7 Histogram of Hole Diameters Histogram of Hole Diameters Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.4 S6–8 Pareto Chart of Factors in an Emergency Room Pareto Chart of Factors in an Emergency Room Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.5 S6–9 Scatterplot of Customer Satisfaction and  Scatterplot of Customer Satisfaction and  Waiting Time in an Upscale Restaurant Waiting Time in an Upscale Restaurant Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.6 S6–10 Reducing Process Variance So that All Parts  Reducing Process Variance So that All Parts  Are within Specification (Tolerance)* Are within Specification (Tolerance)* Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.21a S6–40 *Tolerance: The range within which all individual measurements of units produced is desired to fall Source: Robert W Hall, Attaining Manufacturing Excellence: Just-in-Time Manufacturing, Total Quality, Total People Involvement (Homewood, IL: Dow Jones-Irwin, 1987), p 66 By permission of The McGraw-Hill Companies Reducing Process Variance So that All Parts  Reducing Process Variance So that All Parts  Are within Specification (Tolerance)* (cont’d) Are within Specification (Tolerance)* (cont’d) Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.21b S6–41 *Tolerance: The range within which all individual measurements of units produced is desired to fall Source: Robert W Hall, Attaining Manufacturing Excellence: Just-in-Time Manufacturing, Total Quality, Total People Involvement (Homewood, IL: Dow Jones-Irwin, 1987), p 66 By permission of The McGraw-Hill Companies The Goal of Six Sigma The Goal of Six Sigma Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.22 S6–42 Impact of 1.5 Impact of 1.5  Shift on 3  Shift on 3  Process  Process Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.23a S6–43 Impact of 1.5 Impact of 1.5  Shift on 6  Shift on 6  Process  Process Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.23b S6–44 Defect Rates for Different Levels of  Defect Rates for Different Levels of  Sigma ( Sigma ( ) Assuming a 1.5 Shift in  ) Assuming a 1.5 Shift in  Actual Mean from Design Mean Actual Mean from Design Mean Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.24 S6–45 Taguchi Methods Taguchi Methods • Taguchi Methods –Used for identifying the cause(s) of process variation that reduces the number of tests that are necessary –Use to conduct experiments to determine the best combinations of product and process variables to make a product at the lowest cost with the highest uniformity –Quality loss function • Relates the cost of quality directly to variation in a process âTheMcGrawưHill ã Any deviation from target quality is a loss to society Fundamentals of Operations  Management 4e  Companies, Inc., 2003 S6–46 A Traditional View of the Cost of Variability A Traditional View of the Cost of Variability Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.25 S6–47 Taguchi’s View of the Cost of Variability Taguchi’s View of the Cost of Variability Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.26 S6–48 Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit CS6.1 S6–49 Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit CS6.2 S6–50 Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit CS6.3a S6–51 Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit CS6.3b S6–52 Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit CS6.3c S6–53 Fundamentals of Operations  Management 4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit CS6.4b S6–54 ... Taguchi’s View? ?of? ?the Cost? ?of? ?Variability Taguchi’s View? ?of? ?the Cost? ?of? ?Variability Fundamentals? ?of? ?Operations? ? Management? ?4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.26 S6–48 Fundamentals? ?of? ?Operations? ?... Waiting Time in an Upscale Restaurant Fundamentals? ?of? ?Operations? ? Management? ?4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.6 S6–10 Run Chart? ?of? ?the Number? ?of? ?Daily Errors Run Chart? ?of? ?the Number? ?of? ?Daily Errors Fundamentals? ?of? ?Operations? ?... Fundamentals? ?of? ?Operations? ? Management? ?4e  © The McGraw­Hill  Companies, Inc., 2003 Exhibit S6.22 S6–42 Impact? ?of? ?1.5 Impact? ?of? ?1.5  Shift on 3  Shift on 3  Process  Process Fundamentals? ?of? ?Operations? ?