Seven Quality Control tools Training .ppt
- 1. Quality Improvement: Problem So lving Seven Quality Tools Session : Problem Solving Techniques
- 2. Quality Improvement: Problem So lving Agenda – 7 QC Tools are: • Flow chart • Run Charts • Pareto Diagram • Histogram • Cause and Effect Diagram • Check sheet • Scatter diagram • Control chart
- 3. Quality Improvement: Problem So lving Pareto chart 7 Quality Tools 7 Quality Tools 28 16 12 12 6 4 3 0 5 10 15 20 25 30 Loose Threads Stitching flaws Button problems Material flaws % Complaints
- 4. Quality Improvement: Problem So lving Parreto Diagram Percent from each cause Causes of poor quality M a c h i n e c a l i b r a t i o n s D e f e c t i v e p a r t s W r o n g d i m e n s i o n s P o o r D e s i g n O p e r a t o r e r r o r s D e f e c t i v e m a t e r i a l s S u r f a c e a b r a s i o n s 0 10 20 30 40 50 60 70 (64) (13) (10) (6) (3) (2) (2)
- 5. Quality Improvement: Problem So lving Histogram 0 5 10 15 20 25 Category Frequency 7 Quality Tools 7 Quality Tools
- 6. Quality Improvement: Problem So lving Histogram 0 5 10 15 20 25 30 35 40 1 2 6 13 10 16 19 17 12 16 20 17 13 5 6 2 1
- 7. Quality Improvement: Problem So lving Flowcharts • Flowcharts – Graphical description of how work is done. – Used to describe processes that are to be improved. 7 Quality Tools 7 Quality Tools
- 8. Quality Improvement: Problem So lving Flow Diagrams
- 9. Quality Improvement: Problem So lving Process Chart Symbols Operations Inspection Transportation Delay Storage
- 10. Quality Improvement: Problem So lving Process Flow Chart Step Operation Transport Inspect Delay Storage Distance (feet) Time (min) Description of process 1 2 3 4 5 6 7 8 9 10 11 Unload apples from truck Move to inspection station Weigh, inspect, sort Move to storage Wait until needed Move to peeler Apples peeled and cored Soak in water until needed Place in conveyor Move to mixing area Weigh, inspect, sort Total Page 1 0f 3 480 30 5 20 15 360 30 20 190 ft 20 ft 20 ft 50 ft 100 ft Date: 9-30-00 Analyst: TLR Location: Graves Mountain Process: Apple Sauce
- 11. Quality Improvement: Problem So lving Check sheet (Data sheet) A check sheet is a good starting point for data collection. It usually consists of a simple tally sheet designed around a specific event. You can further analyze the data you collect using other quality tools.
- 12. Quality Improvement: Problem So lving Check Sheet Shifts Shifts Defect Type Defect Type 7 Quality Tools 7 Quality Tools
- 13. Quality Improvement: Problem So lving Check Sheet COMPONENTS REPLACED BY LAB TIME PERIOD: 22 Feb to 27 Feb 1998 REPAIR TECHNICIAN: Bob TV SET MODEL 1013 Integrated Circuits |||| Capacitors |||| |||| |||| |||| |||| || Resistors || Transformers |||| Commands CRT |
- 14. Quality Improvement: Problem So lving Cause And Effect Diagram • Show the relationships between a problem and its possible causes. • Developed by Kaoru Ishikawa (1953) • Also known as … – Fishbone diagrams – Ishikawa diagrams 7 Quality Tools 7 Quality Tools
- 15. Quality Improvement: Problem So lving Cause and Effect “Skeleton” Quality Problem Materials Equipment People Procedures 7 Quality Tools 7 Quality Tools
- 16. Quality Improvement: Problem So lving Fishbone Diagram Quality Problem Machines Measurement Human Process Environment Materials Faulty testing equipment Incorrect specifications Improper methods Poor supervision Lack of concentration Inadequate training Out of adjustment Tooling problems Old / worn Defective from vendor Not to specifications Material- handling problems Deficiencies in product design Ineffective quality management Poor process design Inaccurate temperature control Dust and Dirt
- 17. Quality Improvement: Problem So lving Cause and effect diagrams • Advantages – making the diagram is educational in itself – diagram demonstrates knowledge of problem solving team – diagram results in active searches for causes – diagram is a guide for data collection
- 18. Quality Improvement: Problem So lving Cause and effect diagrams To construct the skeleton, remember: • For manufacturing - the 4 M’s man, method, machine, material • For service applications equipment, policies, procedures, people
- 19. Quality Improvement: Problem So lving Scatter Diagram .
- 20. Quality Improvement: Problem So lving Scatter Diagram What is it ? A scatter diagram is a tool for determining if two variables have an effect on each other. A scatter diagram doesn’t one variable causes another,but it does show the type and strength of relation between them.
- 21. Quality Improvement: Problem So lving How do I do it ? • Collect 50 - 100 paired data samples. • Create horizontal and vertical axes with the possible “cause” on the x-axis and the possible “effect” on the y-axis. • Plot the data on the diagram. If data points are repeated, circle the first point as many times as required.
- 22. Quality Improvement: Problem So lving Following patterns should be be looked out for Positive Correlation As x increases, so does y Negative correlation As x increases, y decreases (or vice versa) No correlation x and y have no effect on each other Volume in thousands errors per thousand Hours of training Accidents Check-in time (minutes) Length of patient stay
- 23. Quality Improvement: Problem So lving Run Chart (Trend chart) • What is it ? A run chart is graphic representation of the variation in process output over time. A run chart reveals trends (or patterns) in your process.
- 24. Quality Improvement: Problem So lving How do I do it ? • Select a process to measure . • Create the horizontal and vertical axes, with time along the x-axis and your quality measure along y- axis. • Plot your trend, such as level of production over time, and connect with a solid line.
- 25. Quality Improvement: Problem So lving Run chart example Run chart for setup 13 11 14 45 33 28 22 42 47 0 5 10 15 20 25 30 35 40 45 50 Duration Percentage of defects
- 26. Quality Improvement: Problem So lving Control Chart 18 12 6 3 9 15 21 24 27 2 4 6 8 10 12 14 16 Sample number Number of defects UCL = 23.35 LCL = 1.99 c = 12.67
- 27. Quality Improvement: Problem So lving Control Charts Control Charts
- 28. Quality Improvement: Problem So lving Pareto Diagram What is it ? • Pareto Diagram was named after 19th-century Italian economist Vilfredo Pareto, Who discovered that 20% of any population held 80% of the wealth. • A Pareto diagram shows you what your biggest problems are in terms of the quality characteristics that best measures your process. • Once you’ve prioritized your problems, you can begin developing a plan for solving them.
- 29. Quality Improvement: Problem So lving Histogram What is it ? A histogram is a graphic display of data. A histogram enables you to see patterns not easily visible in a table of numbers.
Editor's Notes
- #4: Pareto analysis uses an ordered histogram to highlight the major causes of quality problems.
- #6: Histograms are graphical frequency tables that visually capture and display the variation in a set of data.
- #13: A check sheet is a fact-finding tool used to collect data about quality problems. A typical check sheet tallies the number of defects by previously identified categories. The next step is to graph the defects per category in a histogram.
- #16: A cause-and-effect diagram, or fishbone diagram, is a chart showing the different categories of problem causes.
- #19: Scatter diagrams and tightness of points plotted on the graph gives an indication of the strength of the relationship. A cluster of points resembling a straight line indicates the strongest correlation between the variables. In this graph, there is a strong positive correlation between x and y.
- #26: Process control involves monitoring a production process and charting the results on a control chart. If any of the points plotted falls outside the control limits, the process is out-of-control.