MAN 6501 Operations Management
Study Questions

Question # Answer Question # Answer Q 1 Q 11 Q 2 Q 12 Q 3 Q 13 Q 4 Q 14 Q 5 Q 15 Q 6 Q 16 Q 7 Q 17 Q 8 Q 18 Q 9 Q 19 Q 10 Q 20

Quality Control

Q 1: In a single sampling plan the sample size n =5. The submitted lot has on an average 25% defective items. Three acceptance numbers ( c = 0, c =1, and c=2) are being negotiated between the manufacturer and the buyer. Which acceptance number is most desirable from the manufacturer’s viewpoint. You may use the following OC curve to find the answer.

c = 0
c = 1
c = 2

Q 2: In a double sampling plan the two acceptance numbers are: c1 = 8 and c2 = 12. The number of defectives found in the first sample is 9. Therefore, a second sample is taken. What is the maximum number of defectives allowed in the second sample for the lot to be accepted?
a) 0
b) 1
c) 2
d) 3
e) 4

Twenty samples of n = 200 were taken by an operator at a workstation in a production process. The number of defective items in each sample was recorded as follows. Answer Q 3.

Number Number
Sample of Defectives Sample of Defectives
1 12 11 16
2 18 12 15
3 10 13 13
4 15 14 16
5 16 15 18
6 19 16 17
7 17 17 18
8 12 18 20
9 11 19 21
10 14 20 22

Management wants to develop a p-chart. The desired confidence level is 80.0 percent.

Q 3: What is the upper control limit?

Cans of soup are supposed to weigh exactly 16 oz. Inspectors want to develop process control charts. They take eight samples of five boxes and weigh them. They obtain the following data. Answer Q 4, and Q 5.

Sample Mean Range
1 15.2 1.8
2 14.6 0.7
3 16.5 0.5
4 18.1 0.4
5 13.2 0.2
6 16.0 0.4
7 15.9 0.5
8 14.8 0.9

Q 4: What is the upper control limit for the x-bar chart?
Q 5: What is the upper control limit for the R…