7 TRADITIONAL TOOLS OF QUALITY

The Seven Basic Tools stand in contrast to more advanced statistical methods such as survey sampling, acceptance sampling, statistical hypothesis testing, design of experiments, multivariate analysis, and various methods developed in the field of operations research.

1. GE 6757 TOTAL QUALITY MANAGEMENT Faculty F.JUSTIN DHIRAVIAM Assistant Professor Department of Mechanical Engineering 1

2. unIT3 7 TRADITIONAL TOOLS OF QUALITY

3. 7 TRADITIONAL TOOLS OF QUALITY These tools are called as “Basic Tools” because they can be used by people with little formal training. Flow Chart are also known as Stratification or Run Chart. Stratification is a technique that separates data gathered from a variety of sources so that patterns can be seen. Stratification is one of the original 7 tools of quality. A run graph is a graph that displays observed data in a time sequence.

4. 7 TRADITIONAL TOOLS OF QUALITY Statistical Tools Purpose 1 Flow Chart For depicting the essential steps of a process by using standard symbols. 2 Check Sheet For a systematic data gathering by tabulating the frequency of occurrence. 3 Histogram For graphically displaying the frequency distribution of the numerical data. 4 Pareto Diagram For identifying the vital few causes that account for a dominant share of quality loss. 5 Cause & Effect Diagram For identifying and analyzing the potential cause of a given problem. 6 Scatter Diagram For depicting the relationship between two variables. 7 Control Chart For identifying process variations and signaling corrective action to be taken.

5. RELATIONSHIP B/W 7 TOOLS & PDCA S.N Q-7 Tools Plan Do Check Act 1 Flow Chart yes yes yes yes 2 Check Sheet yes yes 3 Histogram yes yes yes 4 Pareto Diagram yes yes yes 5 Cause & Effect Diagram yes yes yes 6 Scatter Diagram yes yes 7 Control Chart yes yes

6. FLOW CHART Also known as process flow chart, flow diagram and process deployment flow. Is a diagrammatic view of the various steps in sequential order that form an overall process in an organization. Used in the quality management for depicting the steps of a process is an easily understandable form by using standard symbols. Flow chart is a simple mapping tool. Is used to document and analyze the connection and sequence of events in a process. Used to create an integrated understanding of the activities and its relationship.

7. STANDARD SYMBOLS FOR CONSTRUCTING FLOW CHART S.No Symbol Name Meaning 1 Terminator For indicating the start or end of the flow process chart 2 Action (Rectangle) For indicating a process or activity or task or operation 3 Decision (Diamond) For indicating a decision 4 Arrows For indicating the direction of flow of the process 5 Link For indicating a link to another page or another flow chart

8. STEPS INVOLVED IN CONSTRUCTION Decide on the process to be investigated Define the start, end and the borders of the process. List the steps in the process by determining the activities decisions inputs and outputs of the process. Draw the chart placing the process steps in the order of their sequencing using the standard symbols. Compare the flow chart with the actual process .

9. CHECK SHEET (DATA COLLECTION SHEET) A check sheet also known as tally sheet Is a form for systematic data gathering and registering to get clear view of the facts. Used to keep track of how often something occurs. Form of check sheet is tailored for each situation/application. Used to indicate the frequency of a certain occurrences.

10. CONSTRUCTION Formulate the objective for collecting data. Decide which data is necessary. Determine who and how data will be analysed . Draw a format to record data Collect and record data problem wise by putting tally lines Start counting Mark on the list the total number of facts which were noticed.

11. CHECK SHEET

12. TYPES OF CHECK SHEETS Process distribution check sheet – used to collect process variability. Defective item check sheet – used to specify the variety of defects occurring with their frequency of occurance Defect location check sheet – used to identify where defects occur on the product Defect factor check sheet – used to monitor the input parameter in a process that might affect the incidents of defects

13. HISTOGRAM Histogram is bar chart/diagram showing a distribution of variable quantities or characteristics. Graphical display of the frequency distribution of the numerical data. Data are displayed as a series of rectangles of equal width and varying heights.

14. USE used to show clearly where the most frequently occurring values are located and the data is distributed. also a tool for determining the maximum process results enables the analyst to quickly visualize the features of a complete set of data.

15. CONSTRUCTION After data collection count the number of data values collected. Determine the range of the data Range = Highest value – Lowest value Divide the data values in groups or classes and count the number of values in each class. Determine the width of the class width of the class = Range / No. of class 5. Draw a frequency table for all values. 6. Construct a histogram based on the frequency table. Mark class limits on horizontal axis and frequency on vertical axis. 7. Finally write title and number of values on the diagram

16. PARETO DIAGRAM PARETO DIAGRAM is a diagnostic tool commonly used for separating the vital few causes that account for a dominant share of quality loss. Tool used to single out the ‘vital few’ from the ‘trivial many’. Also called as 80/20 rule and as ABC analysis. It means only 20% of problems account for 80% of the effects.

17. CONSTRUCTION Obtain data using a check sheet or brainstorm. Arrange the data in descending order starting from largest category to smallest. Calculate the total and % of total that each category represents. Compute the cumulative % Draw bar chart Plot cumulative % line .

18. PARETO ANALYSIS

19. PARETO ANALYSIS

20. PARETO ANALYSIS

21. CAUSE & EFFECT DIAGRAM It is a graphical tabular chart to list and analyse the potential causes of a given problem. Also called as fish bone diagram or Ishikawa diagram.

22. USE Several application in research, manufacturing, marketing, office operations, services etc.. To analyze cause & effect relationships To facilitate the search for solutions of related problems. To standardize existing and proposed operations. To educate and train personnel in decision making and corrective action activities.

23. CONSTRUCTION Define the effect clearly & concisely. Mark the short description of the effect in a box. Then draw a line from this box towards left. List down all possible minor & major causes through brainstorming session. mark the major causes on the branches and minor causes on the sub-branches Look for possible solutions for these causes Introduce the change.

24. CAUSE & EFFECT DIAGRAM

25. CAUSE & EFFECT DIAGRAM

26. SCATTER DIAGRAM Scatter diagram is a simple graphical device to depict the relationship between two variables. graphical component of regression analysis. A scatter diagram consists of horizontal axis containing the measured values of one variable (cause) Vertical axis representing the measurements of the variables (effect). the density and direction of the cloud indicate how the two variables influence each other. This diagram cannot prove that one variable causes the other but they indicate the existence of relationship

27. CONSTRUCTION

28. SCATTER DIAGRAM

29. SCATTER DIAGRAM

30. Scatter diagram

31. CONTROL CHART most widely used tool in SPC. is a graph that displays data taken over time and the variations of this data. can be used to check whether the process is being controlled statistically. Histogram gives a static picture of process variability whereas control chart gives the dynamic performances.

32. CONTROL CHART

33. TYPES OF CONTROL CHARTS Control charts for variables: time, length, temperature, pressure etc.. Control charts for attributes No. of defects, typing errors etc…