In: Statistics and Probability
Q1. (b) Two operators have taken three measurements for each of 10 parts number during a gauge capability study as shown in Table 1.
(i) Does the control chart analysis of the data indicate any potential problem in using the gauge?
(ii) Determine the standard deviation of the measurement error.
Table 1
Part number |
Operator 1 Measurements (mm) |
Operator 2 Measurements (mm) |
||||
1 |
2 |
3 |
1 |
2 |
3 |
|
1 |
50 |
49 |
50 |
50 |
48 |
51 |
2 |
52 |
52 |
51 |
51 |
51 |
51 |
3 |
53 |
50 |
50 |
54 |
52 |
51 |
4 |
49 |
51 |
50 |
48 |
50 |
51 |
5 |
48 |
49 |
48 |
48 |
49 |
48 |
Appendix A:
Table Q1[b]
Sample no. |
x1 |
x2 |
x3 |
x4 |
x5 |
Xbar |
R |
Std. Dev. |
1 |
-30 |
50 |
-20 |
10 |
30 |
|||
2 |
0 |
50 |
-60 |
-20 |
30 |
|||
3 |
-50 |
10 |
20 |
30 |
20 |
|||
4 |
-10 |
-10 |
30 |
-20 |
50 |
|||
5 |
20 |
-40 |
50 |
20 |
10 |
|||
6 |
0 |
0 |
40 |
-40 |
20 |
|||
7 |
0 |
0 |
20 |
-20 |
-10 |
|||
8 |
70 |
-30 |
30 |
-10 |
0 |
|||
9 |
0 |
0 |
20 |
-20 |
10 |
|||
10 |
10 |
20 |
30 |
10 |
50 |
Answer:
Given that,
(b).
Two operators have taken three measurements for each of 10 parts number during a gauge capability study as shown in Table 1.
Part Number | Operator 1 Measurements/ Ukuran (mm) | Operator 2 Measurement Ukuran (mm) | ||||
1 | 2 | 3 | 1 | 2 | 3 | |
1 | 50 | 49 | 50 | 50 | 48 | 51 |
2 | 52 | 52 | 51 | 51 | 51 | 51 |
3 | 53 | 50 | 50 | 54 | 52 | 51 |
4 | 49 | 51 | 50 | 48 | 50 | 51 |
548 | 48 | 49 | 48 | 48 | 49 | 48 |
(i).
Does the control chart analysis of the data indicate any potential problem in using the gauge:
Part Number | Operator 1 Measurements/ Ukuran (mm) | Average1 | Operator 2 Measurement Ukuran (mm) | Average-2 | ||||
1 | 2 | 3 | 1 | 2 | 3 | |||
1 | 50 | 49 | 50 | (50+49+50)/3=49.667 | 50 | 48 | 51 | (50+48+51)=49.667 |
2 | 52 | 52 | 51 | (52+52+51)/3=51.667 | 51 | 51 | 51 | (51+51+51)/3=51 |
3 | 53 | 50 | 50 | (53+50+50)/3=51 | 54 | 52 | 51 | (54+52+51)/3=52.33 |
4 | 49 | 51 | 50 | (49+51+50)/3=50 | 48 | 50 | 51 | (48+50+51)/3=49.667 |
5 | 48 | 49 | 48 | (48+49+48)/3=48.334 | 48 | 49 | 48 | (48+49+48)/3=48.33 |
(ii).
Determine the standard deviation of the measurement error:
Part No. | Average 1 | Average 2 | Absolute Standard deviation of measurement error |
1 | 49.667 | 49.667 | 0 |
2 | 51.667 | 51 | 0.667 |
3 | 51 | 51 | 0 |
4 | 50 | 51 | 1 |
5 | 48.334 | 48.334 | 0 |
Measurement of the part (2) and part (4) derivate by 0.667 and 1 mm tolerance respectively when parts were measured by a different- different operators.