Question

The number of nonconformities found on final inspection of a CD deck is shown in Table below.

a) Can you conclude that the process is in statistical control?

b) What center line and control limits would you recommend for controlling future production?

CD Deck Number	Number of Nonconformities
1	0
2	1
3	1
4	0
5	2
6	1
7	1
8	3
9	2
10	1
11	0
12	3
13	2
14	5
15	1
16	2
17	1
18	1

Answer 1

Answer:- Date:---14/12/2019 Here we are studying the number of nonconformities in a tape of deck. We are interested in studying the number of nonconformities per deck here. So, an appropriate control chart would be C-chart. Here the control limits formulae are , Central line: c Upper Control Limit: c + 3Vc Lower Control Limit: max{c - 3vc, 0}. Ci/m. where c; = number of nonconformities in i-th deck, i=1,2,..,m Where c = ; m=total number of decks considered. here c = 1.5 , UCL = 5.174 , LCL = 0, And the chart is iven below,

C chart showing the number of nonconformiites per Deck UCL=5.174 5. 4 C=1.5 LCL=0 9. 11 13 15 17 Sample Sample Count 3-

a.

all the conformities are with in the limits We can conclude that process is in statstical control