Managing Quality


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Tools of Total Quality Management

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Managing Quality

  1. 1. Chapter 6: Managing Quality ÖZGE ÇELİK 8th April 2011
  2. 2. Learning Objectives <ul><li>Explain quality robust products and Taguchi concepts </li></ul><ul><li>Use the seven tools of TQM </li></ul><ul><li>1. Check Sheets </li></ul><ul><li>2. Scatter Diagrams </li></ul><ul><li>3. Cause-and-Effect Diagrams </li></ul><ul><li>4. Pareto Charts </li></ul><ul><li>5. Flowcharts </li></ul><ul><li>6. Histograms </li></ul><ul><li>7. Statistical Process Control Charts </li></ul>
  3. 3. Taguchi Concepts <ul><li>Engineering and experimental design methods to improve product and process design </li></ul><ul><ul><li>- Identify key component and process variables affecting product variation </li></ul></ul><ul><li>Taguchi Concepts </li></ul><ul><ul><li>- Quality robustness </li></ul></ul><ul><ul><li>- Quality loss function </li></ul></ul><ul><ul><li>- Target-oriented quality </li></ul></ul>
  4. 4. Quality Robustness <ul><li>Ability to produce products uniformly in adverse manufacturing and environmental conditions </li></ul><ul><ul><li>- Remove the effects of adverse conditions </li></ul></ul><ul><ul><li>- Small variations in materials and process do not destroy product quality </li></ul></ul>
  5. 5. Quality Loss Function <ul><li>Shows that costs increase as the product moves away from what the customer wants </li></ul><ul><li>Costs include customer </li></ul><ul><li>dissatisfaction, warranty and service, internal scrap and repair, and costs to society </li></ul><ul><li>Traditional conformance specifications are too simplistic </li></ul>Target-oriented quality
  6. 6. Quality Loss Function Unacceptable Poor Good Best Fair High loss Loss (to producing organization, customer, and society) Low loss Frequency Lower Target Upper Specification Target-oriented quality yields more product in the “best” category Target-oriented quality brings product toward the target value Conformance-oriented quality keeps products within 3 standard deviations L = D 2 C where L = loss to society D = distance from target value C = cost of deviation
  7. 7. Tools of TQM <ul><li>Tools for Generating Ideas </li></ul><ul><ul><li>Check sheets </li></ul></ul><ul><ul><li>Scatter diagrams </li></ul></ul><ul><ul><li>Cause-and-effect diagrams </li></ul></ul><ul><li>Tools to Organize the Data </li></ul><ul><ul><li>Pareto charts </li></ul></ul><ul><ul><li>Flowcharts </li></ul></ul><ul><li>Tools for Identifying Problems </li></ul><ul><ul><li>Histogram </li></ul></ul><ul><ul><li>Statistical process control chart </li></ul></ul>
  8. 8. Seven Tools of TQM / / / / /// / // /// // //// /// // / Hour Defect 1 2 3 4 5 6 7 8 A B C / / // / 1. Check Sheet: An organized method of recording data
  9. 9. Seven Tools of TQM 2. Scatter Diagram: A graph of the value of one variable vs. another variable Absenteeism Productivity
  10. 10. Seven Tools of TQM 3. Cause-and-Effect Diagram: A tool that identifies process elements (causes) that might effect an outcome Cause Materials Methods Manpower Machinery Effect
  11. 11. Cause-and-Effect Diagrams Material (ball) Method (shooting process) Machine (hoop & backboard) Manpower (shooter) Missed free-throws Rim alignment Rim size Backboard stability Rim height Follow-through Hand position Aiming point Bend knees Balance Size of ball Lopsidedness Grain/Feel (grip) Air pressure Training Conditioning Motivation Concentration Consistency
  12. 12. Seven Tools of TQM 4. Pareto Chart: A graph to identify and plot problems or defects in descending order of frequency Frequency Percent A B C D E
  13. 13. Pareto Charts Number of occurrences Room svc Check-in Pool hours Minibar Misc. 72% 16% 5% 4% 3% 12 4 3 2 54 – 100 – 93 – 88 – 72 70 – 60 – 50 – 40 – 30 – 20 – 10 – 0 – Frequency (number) Causes and percent of the total Cumulative percent Data for October
  14. 14. Seven Tools of TQM 5. Flowchart (Process Diagram): A chart that describes the steps in a process
  15. 15. Flow Charts MRI Flowchart <ul><li>Physician schedules MRI </li></ul><ul><li>Patient taken to MRI </li></ul><ul><li>Patient signs in </li></ul><ul><li>Patient is prepped </li></ul><ul><li>Technician carries out MRI </li></ul><ul><li>Technician inspects film </li></ul><ul><li>If unsatisfactory, repeat </li></ul><ul><li>Patient taken back to room </li></ul><ul><li>MRI read by radiologist </li></ul><ul><li>MRI report transferred to physician </li></ul><ul><li>Patient and physician discuss </li></ul>11 10 20% 9 8 80% 1 2 3 4 5 6 7
  16. 16. Seven Tools of TQM 6. Histogram: A distribution showing the frequency of occurrences of a variable Distribution Repair time (minutes) Frequency
  17. 17. Seven Tools of TQM 7. Statistical Process Control Chart: A chart with time on the horizontal axis to plot values of a statistic Upper control limit Target value Lower control limit Time
  18. 18. Statistical Process Control (SPC) <ul><li>Uses statistics and control charts to tell when to take corrective action </li></ul><ul><li>Drives process improvement </li></ul><ul><li>Four key steps </li></ul><ul><ul><li>- Measure the process </li></ul></ul><ul><ul><li>- When a change is indicated, find the assignable cause </li></ul></ul><ul><ul><li>- Eliminate or incorporate the cause </li></ul></ul><ul><ul><li>- Restart the revised process </li></ul></ul>
  19. 19. An SPC Chart Upper control limit Coach’s target value Lower control limit Game number | | | | | | | | | 1 2 3 4 5 6 7 8 9 20% 10% 0% Plots the percent of free throws missed
  20. 20. Inspection <ul><li>Involves examining items to see if an item is good or defective </li></ul><ul><li>Detect a defective product </li></ul><ul><ul><li>Does not correct deficiencies in process or product </li></ul></ul><ul><ul><li>It is expensive </li></ul></ul><ul><li>Issues </li></ul><ul><ul><li>When to inspect </li></ul></ul><ul><ul><li>Where in process to inspect </li></ul></ul>
  21. 21. When and Where to Inspect <ul><li>At the supplier’s plant while the supplier is producing </li></ul><ul><li>At your facility upon receipt of goods from the supplier </li></ul><ul><li>Before costly or irreversible processes </li></ul><ul><li>During the step-by-step production process </li></ul><ul><li>When production or service is complete </li></ul><ul><li>Before delivery to your customer </li></ul><ul><li>At the point of customer contact </li></ul>
  22. 22. Inspection <ul><li>Many problems </li></ul><ul><ul><li>Worker fatigue </li></ul></ul><ul><ul><li>Measurement error </li></ul></ul><ul><ul><li>Process variability </li></ul></ul><ul><li>Cannot inspect quality into a product </li></ul><ul><li>Robust design, empowered employees, and sound processes are better solutions </li></ul>
  23. 23. Source Inspection <ul><li>Also known as source control </li></ul><ul><li>The next step in the process is your customer </li></ul><ul><li>Ensure perfect product to your customer </li></ul>Poka-yoke is the concept of foolproof devices or techniques designed to pass only acceptable product
  24. 24. Service Industry Inspection Attractive, well-organized, stocked, good lighting Rotation of goods, organized, clean Neat, courteous, very knowledgeable Display areas Stockrooms Salesclerks Nordstrom Department Store Standard What is Inspected Organization
  25. 25. Attributes Versus Variables <ul><li>Attributes </li></ul><ul><ul><li>Items are either good or bad, acceptable or unacceptable </li></ul></ul><ul><ul><li>Does not address degree of failure </li></ul></ul><ul><li>Variables </li></ul><ul><ul><li>Measures dimensions such as weight, speed, height, or strength </li></ul></ul><ul><ul><li>Falls within an acceptable range </li></ul></ul><ul><li>Use different statistical techniques </li></ul>
  26. 26. TQM In Services <ul><li>Service quality is more difficult to measure than the quality of goods </li></ul><ul><li>Service quality perceptions depend on </li></ul><ul><ul><li>Intangible differences between products </li></ul></ul><ul><ul><li>Intangible expectations customers have of those products </li></ul></ul>
  27. 27. Service Quality The o perations m anager must recognize: <ul><li>The tangible component of services is important </li></ul><ul><li>The service process is important </li></ul><ul><li>The service is judged against the customer’s expectations </li></ul><ul><li>Exceptions will occur </li></ul>
  28. 28. Determinants of Service Quality <ul><li>Reliability </li></ul><ul><li>Responsiveness </li></ul><ul><li>Competence </li></ul><ul><li>Access </li></ul><ul><li>Courtesy </li></ul><ul><li>Communication </li></ul><ul><li>Credibility </li></ul><ul><li>Security </li></ul><ul><li>Understanding/ knowing the customer </li></ul><ul><li>Tangibles </li></ul>
  29. 29. Service Recovery Strategy <ul><li>Managers should have a plan for when services fail </li></ul><ul><li>Marriott’s LEARN routine </li></ul><ul><ul><li>L isten </li></ul></ul><ul><ul><li>E mpathize </li></ul></ul><ul><ul><li>A pologize </li></ul></ul><ul><ul><li>R eact </li></ul></ul><ul><ul><li>N otify </li></ul></ul>
  30. 30. Managerial Implications <ul><li>We will have plan for when services fail. </li></ul><ul><li>We will recognize that the service is judged against the customer’s expentations. </li></ul>