CQE Handbook 3 rd edition Ch. 27 Quality Control Tools

1. CQE Handbook 3rd edition Ch. 27 Quality Control Tools Presented by Dr. Joan Burtner Certified Quality Engineer Associate Professor of Industrial Engineering and Industrial Management

2. Seven Basic Tools as defined by the American Society for Quality (ASQ) • Check Sheet • Pareto Chart • Scatter Diagram • Histogram • Cause-and-Effect Diagram • Flowchart • Control Chart Dr. Joan Burtner, Associate Professor of Industrial Engineering

3. Basic Quality Tool :Check Sheet • Also known as a tally sheet • Helps gather data on the frequency of occurrence of particular events or defects • Check sheet design often requires prior knowledge of the process Dr. Joan Burtner, Associate Professor of Industrial Engineering

4. Basic Quality Tool :Check Sheet Mechanics • Design the check sheet for a given application. sheet • Record the data. • Use the data for analysis or input to additional graphical tools such as Pareto charts or histograms. Dr. Joan Burtner, Associate Professor of Industrial Engineering

5. Basic Quality Tool :Pareto Chart • Pareto (an 1800s Italian economist) noted that 80 percent of the wealth in Italy was held by 20 percent of the population. This is called the Pareto Principle. • Juran (20th century) applied the Pareto Principle to quality improvement • vital few • useful many (sometimes called trivial many) • Mechanics • Minitab offers a built-in function for the Pareto chart • Manual method: Count items in each category. Plot on graph in order of descending frequency. Dr. Joan Burtner, Associate Professor of Industrial Engineering

6. Basic Quality Tool :Pareto Chart • Causes are frequently documented in a check sheet which is used to generate a Pareto chart • Managers use Pareto charts to help focus or prioritize process improvement efforts • The chart to the right was generated in Minitab Dr. Joan Burtner, Associate Professor of Industrial Engineering

7. Basic Quality Tool :Scatter Diagram • Also known as an X-Y graph • Purpose is to graphically display indications of a relationship between two variables • Caution: A statistical correlation does not guarantee a direct cause and effect. • Caution: Excel will yield the equation for a straight line “best fit” Dr. Joan Burtner, Associate Professor of Industrial Engineering

8. Basic Quality Tool :Scatter Diagram Mechanics • Select two variables of interest. • Set a scale for the axes. • Collect and chart the data. • Evaluate the results. • Linear/nonlinear • Positive/negative Dr. Joan Burtner, Associate Professor of Industrial Engineering

9. Basic Quality Tool :Histogram • Purpose is to graphically depict the frequency of occurrence , where occurrences are sorted into categories of a defined range along a continuous scale • X-axis shows cell boundaries • Y-axis shows cell frequency • Shape of the bars is only a rough indication of the distribution Dr. Joan Burtner, Associate Professor of Industrial Engineering

10. Basic Quality Tool :Histogram Mechanics • Determine the amount of data to be collected • Determine number of columns or bins to be used • Collect and record data • Prepare the graphic and graph the data (Minitab and Excel have built-in functions for histograms) • X-axis shows bin boundaries • Y-axis shows bin frequency Dr. Joan Burtner, Associate Professor of Industrial Engineering

11. Basic Quality Tool :Cause-and-Effect Diagram • Used to show the many different causes that may contribute to a problem (effect) • Causes are frequently generated through brainstorming sessions • Other names • Fishbone diagram • Ishikawa diagram • C-E diagram • 4 M diagram • 4 P diagram • 6 M diagram Methods Machine Flat Tire Materials Man Dr. Joan Burtner, Associate Professor of Industrial Engineering

12. Basic Quality Tool :Cause-and-Effect Diagram Mechanics • Select a single problem or opportunity (effect) • Identify major causes • Identify the minor causes associated with each major cause. (Add structure.) • Identify additional cause structure. (Add detail.) • Note: Ideas are frequently generated through brainstorming sessions conducted BEFORE major/minor causes are identified. People Policy Difficulty finding billing office Procedure Plant Dr. Joan Burtner, Associate Professor of Industrial Engineering

13. Basic Quality Tool :Popular C-E Diagram Categories • 4M Chart • Man • Machine • Methods • Materials • 4P Chart • People • Policies • Procedures • Plant • 6M Chart • Man • Machine • Methods • Materials • Mother Nature • Measurement Dr. Joan Burtner, Associate Professor of Industrial Engineering

14. Basic Quality Tool :Flowchart Load • Purpose is to provide a graphic representation of the elements, components, or tasks associated with a process • Maps the sequence of steps and decision points in a process • Helps group to have common understanding of the process Wash Dry Paint Cure Distribute Scrap Dr. Joan Burtner, Associate Professor of Industrial Engineering

15. Basic Quality Tool :Flowchart Mechanics • Select a start and stop point. • List major steps/tasks and decision points. (Show in sequential order.) • Use standardized graphical symbols to document the process. • Review results. (Verify and refine as necessary.) • Note: It is standard protocol to have more than one person independently verify results. Start Basic processing Flow Decision Dr. Joan Burtner, Associate Professor of Industrial Engineering

16. Basic Quality Tool :Control Chart • Purpose • Indicates how a process behaves over time • Shows when a process is being influenced by special causes • Chart consists of UCL, CL, LCL, and data points • Examined for nonrandom patterns • See Chapter 37 for mechanics of construction Dr. Joan Burtner, Associate Professor of Industrial Engineering

17. Contact Information • Email: Burtner_J@Mercer.edu • US Mail: Dr. Joan Burtner, Chair Department of Industrial Engineering and Industrial Management Mercer University School of Engineering 1501 Mercer University Drive Macon, GA 31207 • Phone: (478) 301- 4127 Dr. Joan Burtner, Associate Professor of Industrial Engineering