Refer to Exercise 8-32. If the weighting systems were different (i.e., 10, 5, and 1), how would the centerline and the control limits change for the U-chart? Discuss changes, if any, in the inferences made about the process.

Exercise 8-32

Nonconformities in automobiles fall into three categories: serious, major, and minor. Twenty-five samples of five automobiles are chosen, and the total number of nonconformities in each category is reported. Table 8-30 shows the results. Assuming a weighting system of 50, 10, and 1 for serious, major, and minor nonconformities, respectively, construct a demerits per unit control chart. Revise the control limits if necessary, assuming special causes for points that are out of control.

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TABLE 8-30 Serious Major Minor Serious Major Defects Minor Sample Defects Defects Defects Sample Defects Defects 1 5 8 14 7 12 3 2 15 8 3 1 16 4 3 4 2 1 17 1 5 5 6 8. 18 3 2 6. 3 19 5 8 7 1 10 20 2 6 8 1 2 21 1 1 4 9 4 22 3 10 10 2 6 23 12 11 1 3 2 24 4 7 12 5 8 25 2 4 13 9