Pareto Chart
1. Explain the purpose of a Pareto Chart. Give an example of when one would be used?
2. The following are a list of possible causes for a defect with the reported occurrence of each. Please use this information to create a Pareto Chart in Excel. (Insert a screen shot into the body of this exam for credit) *Explain what you would do based on your results*
Possible Causes Number of Defects
Defective Material 24
Operator Error 141
Machine Error 75
Environmental Factor 12
Process Error 21
Measurement Failure 18
Intentional Variance 9
3. Describe the origin and use of cause-and-effect diagrams. Be sure to include its purpose, components, and the 6M’s for non-service and 6P’s service industries.
4. How would a check sheet be used in a modern production facility? Please give examples of both a data check sheet and location check sheet.
Your process has a normal histogram with ? located at 10mm, 1? points at 9.9 and 10.1mm, 2? points at 9.8 and 10.2mm, and 3? points at 9.7 and 10.3mm.
Answer the following questions regarding the above histogram
5a. If your customer will accept parts measuring between 9.7 and 10.3 mm, how many parts of every 1000 produced would you expect to scrap?
5b. If your customer notified you that henceforth it would accept only parts between 9.9 and 10.1 mm, what would you anticipate your scrap rate to be?
5c. What would have to be done to bring the scrap rate at this new customer requirement back down to what it had been at the former customer specification?
5d. Compared to the bell curve above, what would the new histogram have to look like?
6. The following are images of Scatter Diagrams. Explain the relationship that we see.
7. Explain the purpose of Stratification and how it differs from a Scatter Diagram.
8. Using Excel, plot the following Data into a Scatter Diagram and explain the relationship. Use the Year and Price columns. (Insert a screen shot into the body of this exam for credit)
Gas Prices
Year My Age Gas Prices
1950 0 $0.06
1955 5 $0.12
1965 15 $0.15
1960 10 $0.27
1970 20 $0.52
1975 25 $0.64
1980 30 $0.76
1985 35 $0.89
1990 40 $1.10
1995 45 $1.19
2000 50 $1.40
9. What is the difference between Run Charts and Control Charts? Be sure to include normal causes (statistical variance) and special causes.
11. Use the following data set to construct a Control Chart in Excel. (Insert a screen shot into the body of this exam for credit)
Date Coded Thickness Date Coded Thickness
1-Jan-13 206 13-Jan-13 218
2-Jan-13 204 14-Jan-13 188
3-Jan-13 206 15-Jan-13 210
4-Jan-13 205 16-Jan-13 209
5-Jan-13 214 17-Jan-13 208
6-Jan-13 215 18-Jan-13 203
7-Jan-13 205 19-Jan-13 204
8-Jan-13 202 20-Jan-13 200
9-Jan-13 210 21-Jan-13 198
10-Jan-13 212 22-Jan-13 200
11-Jan-13 208 23-Jan-13 195
12-Jan-13 207 24-Jan-13 201