Problem -
Boston Electric Generators has been getting many complaints from its major customer, Home Station, about the quality of its shipments of home generators. Daniel Shimshak, the plant manager, is alarmed that a customer is providing him with the only information the company has on shipment quality. He decides to collect information on defective shipments through a form he has asked his drivers to complete on arrival at customers' stores. The forms for the first 279 shipments have been turned in. They show the following over the past 8 weeks:
|
Week
|
No. of Shipments
|
No. of Shipments with Defects
|
Reason for Defective Shipment
|
|
Incorrect Bill of Lading
|
Incorrect Truck - Load
|
Damaged Product
|
Trucks Late
|
|
1
|
23
|
5
|
2
|
2
|
1
|
|
|
2
|
31
|
8
|
1
|
4
|
1
|
2
|
|
3
|
28
|
6
|
2
|
3
|
1
|
|
|
4
|
37
|
11
|
4
|
4
|
1
|
2
|
|
5
|
35
|
10
|
3
|
4
|
2
|
1
|
|
6
|
40
|
14
|
5
|
6
|
3
|
|
|
7
|
41
|
12
|
3
|
5
|
3
|
1
|
|
8
|
44
|
15
|
4
|
7
|
2
|
2
|
Even though Daniel increased his capacity by adding more workers to his normal contingent of 30, he knew that for many weeks he exceeded his regular output of 30 shipments per week. A review of his turnover over the past 8 weeks shows the following:
|
Week
|
No. of New Hires
|
No. of Terminations
|
Total No. of Workers
|
|
1
|
1
|
0
|
30
|
|
2
|
2
|
1
|
31
|
|
3
|
3
|
2
|
32
|
|
4
|
2
|
0
|
34
|
|
5
|
2
|
2
|
34
|
|
6
|
2
|
4
|
32
|
|
7
|
4
|
1
|
35
|
|
8
|
3
|
2
|
36
|
a) Develop a scatter diagram using total number of shipments and number of defective shipments. Does there appear to be any relationship?
b) Develop a scatter diagram using the variable "turnover" (number of new hires plus number of terminations) and the number of defective shipments. Does the diagram depict a relationship between the two variables?
c) Develop a Pareto chart for the type of defects that have occurred.
d) Draw a fish-bone chart showing the possible causes of the defective shipments.