Analysis project

Please consider the numbers below. Both data sets were captured during a single week of production.

Data Set One was taken first, but it didn’t show what the manager wanted, so she told her production supervisor to try again.

The manager has been asked to “demonstrate process capability.” (In this company, 4-sigma quality is the expected standard.)

Data Set Two was from the same process, without any changes to the process, but as you can see, the sample size and number of samples was changed.

Please draw Mean and Range control charts, calculate Capability, and comment on what action this manager might want to take.

HINT #1: To calculate capability, you need the s of the raw data set, preferably estimated using large samples. You don’t have the raw data set, and the sample sizes are not as large as you might want.

But you can estimate the s by using the known fact that A2*R_bar is approximately equal to 3s/sqrt(n)

Data Set One shows the summary results from 18 different samples, with n=20 measurements in each sample.

Data Set Two shows the summary results from 27 different samples, with n=5 measurements in each sample.

HINT #2: Don’t be fooled, there’s something odd about this data. One data set indicates “process capable”, while the other does not, even though the data comes from the exact same process.

What’s going on? The results of this test are being manipulated somehow. What is it?

HINT #3: You will get nowhere on this assignment if you forget the difference between “control” and “capability”. I have asked you to make control charts, and also to calculate process capability.

The “control” part of the assignment is completely unrelated to the “capability” part of this assignment. Learn the difference.

Summary of Data Set One

Summary of Data Set Two

Target Spec = 45.00

Sample

Mean

Range

Sample

Mean

Range

Tolerance = +0.75

1

45.01

0.85

1

44.96

0.42

2

44.99

0.89

2

44.98

0.39

3

45.02

0.86

3

44.96

0.41

4

45.00

0.91

4

44.97

0.37

5

45.04

0.87

5

45.02

0.39

6

44.98

0.9

6

45.03

0.40

7

44.91

0.86

7

45.04

0.39

8

45.04

0.89

8

45.02

0.42

9

45.00

0.85

9

45.08

0.38

10

44.97

0.91

10

45.12

0.40

11

45.11

0.84

11

45.07

0.41

12

44.96

0.87

12

45.02

0.38

13

45.00

0.86

13

45.01

0.41

14

44.92

0.89

14

44.98

0.40

15

45.06

0.87

15

45.00

0.39

16

44.94

0.86

16

44.95

0.41

17

45.00

0.85

17

44.94

0.43

18

45.03

0.88

18

44.94

0.40

19

44.87

0.38

20

44.95

0.41

21

44.93

0.39

22

44.96

0.41

23

44.99

0.40

24

45.00

0.44

25

45.03

0.42

26

45.04

0.38

27

45.03

0.40

Analysis project

Case: Wendy’s International Expansion

GENETICALLY MODIFIED FOODS