SPC Assignment
Fred's Pizza has been in operation for 26 weeks. For quality purposes, each week Fred randomly calls 25 customers who have had pizza delivered to their homes. He asks them one simple "yes or no" question - were they satisfied with their order?
Fred has been collecting these responses since the time his business opened.
The table below lists, by week, the number of customers who reported they were NOT satisfied with their order.
|
|
Patrons
|
Not
|
|
|
Surveyed
|
Satisfied
|
|
1
|
25
|
3
|
|
2
|
25
|
4
|
|
3
|
25
|
11
|
|
4
|
25
|
6
|
|
5
|
25
|
3
|
|
6
|
25
|
6
|
|
7
|
25
|
2
|
|
8
|
25
|
4
|
|
9
|
25
|
5
|
|
10
|
25
|
5
|
|
11
|
25
|
3
|
|
12
|
25
|
6
|
|
13
|
25
|
6
|
|
14
|
25
|
5
|
|
15
|
25
|
3
|
|
16
|
25
|
6
|
|
17
|
25
|
5
|
|
18
|
25
|
4
|
|
19
|
25
|
4
|
|
20
|
25
|
4
|
|
21
|
25
|
3
|
|
22
|
25
|
4
|
|
23
|
25
|
4
|
|
24
|
25
|
3
|
|
25
|
25
|
7
|
|
26
|
25
|
6
|
Fred has employed you to consult on this matter. Please perform the following:
1. Create appropriate control chart(s) to analyze the problem.
2. Is the process in or out of control? Why do you feel this to be the case? Be sure to identify all evidence.
3. Based off your interpretation of the control chart, what recommendations do you have for Fred? What specific things might Fred investigate? Limit your response to a single paragraph.
Be sure to include the table having all of your calculations in addition to your control chart.
You will be graded on the correct analysis of the data, the clear presentation of your homework (including the table / chart), as well as the logic and completeness of your recommendation.