Discuss the below:
Q: A process that produces titanium forgings for automobile turbocharger wheels is to be controlled through use of a fraction nonconforming chart. Initially, one sample of size 150 is taken each day for 20 days, and the results shown here are observed.
|
Day
|
Nonconforming Units
|
|
1
|
3
|
|
2
|
2
|
|
3
|
4
|
|
4
|
2
|
|
5
|
5
|
|
6
|
2
|
|
7
|
1
|
|
8
|
2
|
|
9
|
0
|
|
10
|
5
|
|
11
|
2
|
|
12
|
4
|
|
13
|
1
|
|
14
|
3
|
|
15
|
6
|
|
16
|
0
|
|
17
|
1
|
|
18
|
2
|
|
19
|
3
|
|
20
|
2
|
(a) Establish a control chart to monitor future production.
(b) What is the smallest sample size that could be used for this process and still give a positive lower control limit on the chart?