paint booth operation runs 5 days per week B u s i n e s s F i n a n c e

Quality Control and Improvement

Refer to the following text and data for the questions in this quiz.

A paint booth operation runs 5 days per week. As the production supervisor, you track the number of errors produced by the paint booth by week. Errors can be of any type (over spray, inadequate coverage, etc.), may occur on one or more pieces of equipment, and the number and type of equipment painted varies greatly. Ten weeks of data were collected and the number of errors identified are found in the following table. Construct a control chart with 3-sigma control limits to determine if the process is in control.

Week	Number of errors
1	5
2	4
3	5
4	4
5	4
6	3
7	0
8	2
9	0
10	3

1. (6 points) Which control chart is most appropriate for the paint booth data?

a. C Chart

b. P Chart

c. Xbar and R Charts

d. Xbar and S Charts

2. (3 points) What is the center line for the control chart?

a. 3

b. 10

c. 0

d. 8.2

3. (3 points) What is the lower control limit for the control chart?

a. 0

b. -2.2

c. 3

d. 1

4. (3 points) What is the upper control limit for the control chart?

a. 8.2

b. 5

c. 12

d. 5.2

5. (3 points) Draw the control chart and determine if the process is in control. Which of the following statements is true?

a. The process is out of control because there is a shift in the data after Week 5.

b. The process is in control because all of the points are inside the control limits.

c. The process is out of control because there are data points outside of the control limits.

d. The process is in in control because no patterns are present.

6. (6 points) After investigating, you determine that there is a special cause. The paint booth had become wore and was overhauled after Week 5. What, if anything, should you do to continue monitoring the paint booth operation?

a. Recompute the control chart using just the Week 6 through Week 10 data and continue to monitor the process.

b. Continue to monitor the process on the same control chart.

c. Average the data to develop a control chart that accounts for both the poor performance in Weeks 1-5 and teh better performance in Weeks 6-10

d. Nothing.

7. (6 points) You recalculate the control chart using the data for the new (overhauled) process. What is the LCL, CL, and UCL, respectfully?

a. 0, 1.6, 5.39

b. -2.19, 1.6, 5.39

c. 0, 1.6, 6.4

d. -2.19, 1.6, 6.4