Multi-Variable Chart Multi-Variable Chart SinterTime MetalType Strength 100 1 23 100 1 20 100 1 21 100 2 22 100 2 19 100 2 20 100 3 19 100 3 18 100 3 21 150 1 22 150 1 20 150 1 19 150 2 24 150 2 25 150 2 22 150 3 20 150 3 19 150 3 22 200 1 18 200 1 16 200 2 21 200 2 23 200 2 20 200 3 20 200 3 22 200 3 24 Multi-Variable Chart Multi-variable charts are a way of presenting analysis of variance data in a graphical form providing a "visual" alternative to analysis of variance. These charts may also be used in the preliminary stages of data analysis to get a look at the data. The chart displays the means at each factor level for every factor. Example: The given data represent the effect of sintering time for different material on the measured strength. It required to analyze the data and found the importance factor compunctions

Solution: Minitab

Diagnostic Charts There are a variety of diagnostic techniques available to investigate quality problems. Two of the more prominent of these techniques are Pareto charts and fishbone diagrams. Pareto Charts A Pareto chart, named after Vilfredo Pareto, is a type of chart that contains both bars and a line graph, where individual values are represented in descending order by bars, and the cumulative total is represented by the line The left vertical axis is the frequency of occurrence, but it can alternatively represent cost or another important unit of measure. The right vertical axis is the cumulative percentage of the total number of occurrences, total cost, or total of the particular unit of measure. The cumulative function is a concave because of the decreasing order of reasons. For the example above, in order to lower the amount of late arrivals by 78%, it is sufficient to solve the first three issues. The purpose of the Pareto chart is to highlight the most important among a set of factors. In quality control, it often represents the most common sources of defects, the highest occurring type of defect, or the most frequent reasons for customer complaints, and so on. Wilkinson (2006) devised an algorithm for producing statistically based acceptance limits (similar to confidence intervals) for each bar in the Pareto chart.

20% of the people cause 80% of the problems

Total = 112 defects

Example: A tourist resort is concerned with water usage, particularly in single family homes. He would like to develop a plan to reduce the water usage. A 100 homes were selected as sample and typical daily water usage for various purposes were recoded. These sample results are as follows: water usage sources lit/day Laundering 24.9 Lawn 143.7 Bathing 10.4 Cooking 5.1 Swimming Pool 106.7 Dishwashing 12.3 Carwhashing 28.3 Drinking 7.9 الحديقة Solution: