Question

For a long time you have noticed that your panels have many dirt and grease spots when they are packed and shipped out of your department. The customer says that something must be done to improve the situation. Can this problem be solved by the people on the production floor, or must a management team take the necessary action to bring about improvement?

Someone took the time to inspect 48 parts at the final packing operation each day for twenty days. Using this data, try to determine whether the problem is due to assignable causes or due to the way the process is set up.

Day	No. Defectives
1	30
2	27
3	34
4	23
5	20
6	33
7	22
8	24
9	18
10	34
11	25
12	20
13	24
14	23
15	16
16	19
17	32
18	26
19	25
20	25

Answer 1

From the given data

Observations	di	pi= di /n
1	30	0.75
2	27	0.675
3	34	0.85
4	23	0.575
5	20	0.5
6	33	0.825
7	22	0.55
8	24	0.6
9	18	0.45
10	34	0.85
11	25	0.625
12	20	0.5
13	24	0.6
14	23	0.575
15	16	0.4
16	19	0.475
17	32	0.8
18	26	0.65
19	25	0.625
20	25	0.625
Total:	500	12.5

Here All sample points lies between LCL and UCL therefore the process is under control