Class 22: Quality Management OPSM301 Spring 2012 Class 22: Quality Management

Quality Is That which makes anything such as it is - Dictionary Fitness for use - J. Juran and ASQ Conformance to requirements - P. Crosby Closeness to the target - deviations mean loss to the society - G. Taguchi Providing full customer satisfaction at the most economical levels - A. Feigenbaum Eight dimensional - Performance, Features, Conformance, Reliability, Serviceability, Durability, Aesthetics, and Perception - D. Garvin Copyright © 2013 Pearson Education Inc. publishing as Prentice Hall

Variability = Actual - Expected Customer Needs - Product Design Product Design - Process Capability Process Capability - Process Performance Process Performance - Product Performance Product Performance - Customer Perception

Ways in Which Quality Can Improve Profitability Sales Gains Improved response Higher prices Improved reputation Improved Quality Increased Profits Reduced Costs Increased productivity Lower rework and scrap costs Lower warranty costs

Quality Costs Cost of Control (Quality, Conformance) Prevention costs: reducing the potential for defects Appraisal costs: evaluating products Cost of Failure of Control (Unquality, non-conformance) Internal failure costs:of producing defective parts or service External failure costs: occur after delivery

Early Defect Detection Saves Stage: At Source Next Process End of Line Final Inspection End User Cost: Impact: • Little • Minor • Rework • Much rework • Warranty delay • Reschedule • Delivery delay • Complaints • Inspect more • Reputation • Market share Prevention Saves Even More!

International Quality Standards ISO 9000 series Common quality standards for products sold in Europe (even if made in U.S.) 2000 update places greater emphasis on leadership and customer satisfaction ISO 14000 series Environmental management Auditing Performance evaluation Labeling Life cycle assessment

TQM: Continuous Process Improvement Measurement External and Internal Analysis Analyze Variation Control Adjust Process Improvement Reduce Variation Innovation Redesign Product/Process D A C P Improve Innovate D A C P Improve Control

Analytical Tools for Continuous Improvement Process Analysis Pareto Charts Histograms Scatter Diagrams Fish-Bone Charts Control Charts

Seven Tools for TQM

Check Sheet Type of Defect Number of Defective Flow Units Cost Response Time Customization Service Quality Garage Quality

Pareto Analysis The purpose of Pareto Analysis is to identify and highlight major symptoms of major quality problems It is based on the premise that usually a small number of faults cause the majority of malfunctions (to separate the vital few and trivial many)

Developing Pareto Analysis Define classification of defects to be monitored Define the period of time over which the assessment will be made Total the frequency of occurrence of each class of defects over the period Plot the histogram and cumulative distribution of the classes in descending order of the frequency occurrence Identify the classes that constitute the majority of defect occurrences

“80 percent of the problems are due to 20 percent of the causes” Pareto Analysis -100% Frequency Percentage -50% -0% A B C D E F Pareto Law (80/20 Rule): “80 percent of the problems are due to 20 percent of the causes”

Fish-Bone Diagram Also known as cause-and-effect diagram, or Ishikawa diagram Pareto analysis is used to identify key problems or symptoms, Fish-Bone diagram is used to sort causes of the problems Brain storming sessions of groups of workers needed It is a very valuable educational tool

Fish-Bone Diagram Used to find problem sources/solutions Other names Fish-bone diagram, Ishikawa diagram Steps Identify problem to correct Draw main causes for problem as ‘bones’ Ask ‘What could have caused problems in these areas?’ Repeat for each sub-area. This slide introduces the Cause and Effect Diagram. The next several slide show the development of a simple example. If time is available, it would be helpful to ask students to develop their own examples.

Cause-and-Effect Diagrams Material (ball) Method (shooting process) Size of ball Lopsidedness Grain/Feel (grip) Air pressure Follow-through Hand position Aiming point Bend knees Balance Missed free-throws Training Conditioning Motivation Concentration Consistency Manpower (shooter) Rim alignment Rim size Backboard stability Rim height Machine (hoop & backboard)

Weight data for 20 days-Table 1 Time 1 2 3 4 5 6 7 8 9 10 9:00 81 82 80 74 75 83 86 88 11:00 73 87 79 84 13:00 85 76 91 89 15:00 90 78 77 17:00 Time 11 12 13 14 15 16 17 18 19 20 9:00 86 88 72 84 76 74 85 82 89 11:00 83 79 80 13:00 81 78 90 15:00 77 92 17:00 87

Histogram 2 4 6 8 1 7 9 Weight (kg) Frequency