Comparing Quality of Processes Using Descriptive Statistics

 

A quality inspector is to investigate the performance of two soft drink bottling plants (plant A & plant B). Each of the bottling plants was asked to take a random sample of 25 bottles for inspection. The actual amount of soft drink in each of the “2-liter” bottle sampled was measured and recorded. The company wishes that these bottling plants can operate in a way that is cost effective and also fulfill one of the most important goals that is customer satisfaction in terms of having enough (at least 2 liters) soft drink in the bottle. Each of the bottles can contain at most 2.2 liter of soft drink, if there is any data value higher than 2.2 should be considered as error and such a data value should not be considered in the study. The data is listed at the bottom of the page.

 

Write a report about your analysis on the data observed from these bottling plants. In your report,

1)      You need to present statistical charts and descriptive measures that you used in this analysis.

2)      Which of the plants has most urgent issue related customer satisfaction?

3)      You must comment on the performance of these two bottling plants in terms of the amount of soft drink in the bottles and related to precision and accuracy, and also make recommendations for improvements. (Accuracy can usually be improved by calibration and adjusting volume control of the coke dispensing system, but, depending on situations, improving the precision usually requires more work.)

4)      In your opinion which of the two plants has more serious quality problem? Explain your answer using the statistics that you have reported.

 

(Write this report as if you are a quality control consultant reporting to your client. Your paper will be graded based on the accuracy, organization, and professionalism. Each chart and table should be properly labeled with title. You may follow the labeling format as those charts and tables in the textbook. More charts does not mean better grade.)

 

Data: Amount of soft drink in the bottles (in liter)

 

Plant A

Plant B

1

2.010

2.215

2

2.000

2.113

3

2.011

2.165

4

2.016

2.135

5

1.995

2.133

6

2.016

2.140

7

2.012

2.077

8

2.016

2.825

9

2.004

2.144

10

2.024

2.019

11

2.026

2.138

12

2.023

2.107

13

2.005

2.188

14

2.015

1.978

15

2.007

1.965

16

2.012

2.077

17

2.000

2.153

18

2.000

2.057

19

2.013

2.033

20

2.005

2.123

21

2.005

2.154

22

1.991

2.030

23

2.016

2.174

24

2.003

2.047

25

2.019

2.172