Question

Federal Scanline, Inc. uses a scanner on a conveyor line which scans 1,000 packages per hour. Packages which have defective labels or detectable damage to the package are automatically offloaded and hand-sorted by severity of defects, on a scale of 1-5. A minor defect is a 1, such as a single number missing from a zip code. A 3 would be a moderate defect, such as a missing addressee name or partially missing address. A 5 would be a critical defect, such as a severely damaged package or missing address label. Construct a c-chart for the 30 samples showing critical defects from the data in the table in the worksheet Prob. 8-46 in the C08Data.xlsx file and interpret the results.

Federal Scanline
	Number of
Sample	Nonconformances
1	12
2	11
3	1
4	10
5	5
6	4
7	1
8	9
9	4
10	6
11	5
12	7
13	10
14	9
15	13
16	1
17	14
18	11
19	11
20	12
21	9
22	8
23	6
24	14
25	5
26	11
27	10
28	7
29	3
30	11
	240

Answer 1

As given.

Total Number of Nonconformances = 240

For C-chart-

C-bar = Average of Non Conformances = 240/30 = 8

UCL = C-bar + 3*(C-bar)^(1/2)

UCL = 8 + 3*(8)^(1/2)

UCL = 16.485

LCL = C-bar - 3*(C-bar)^(1/2)

LCL = 8 - 3*(8)^(1/2)

LCL = -0.485

LCL = 0 (Since value is negative)

Below is the screenshot of the C chart -

From above, it is clear that Non Conformances is within the acceptable control limit range as per C-Chart.