Statistics Assignment
Improve Phase Assignment
This phase is referred to as the proactive phase since the levels of input factors are changed to observe the effect on the output variable.
This phase will consider Analysis of Variance (ANOVA One Way and Two Way) and Design of Experiment (DOE)
Referred To:
Text Book: Implementing Six Sigma Smarter Solutions using Statistical Methods 2nd Edition By Forrest W Breyfogle III
a. Chapter 24
b. Chapter 25
Chapter 24
1. Exercise 7
2. Exercise 8
3. A manufacturer of steel wants to test the effect of the method of manufacture on the tensile strength of a particular type of steel. Four different methods have been tested and the data shown in Table 1. Test the significance of the effect at α = 0.05
Table 1
Methods Tensile Strength
|
1 |
2650 |
2765 |
2750 |
2600 |
|
2 |
2985 |
2975 |
2865 |
2890 |
|
3 |
2775 |
2620 |
2690 |
2700 |
|
4 |
2900 |
2885 |
2850 |
2950 |
Chapter 25
1. Exercise 2
2. A 2 Factor experiment was conducted to test whether the given factors affect the response variable. The data shown in Table 5 were collected for 3 levels for A and B respectively with 4 replicates.
i). Using α = 0.05, test for the significance of all possible effects.
Table 5
Factor A
Factor B 600 650 700
|
1 |
142, 113, 126, 130 |
115, 129, 109, 98 |
135, 120, 115, 110 |
|
2 |
122, 104, 118, 138 |
112, 104, 100, 119 |
144, 132, 120, 139 |
|
3 |
110, 126, 138, 120 |
122, 100, 118, 109 |
142, 130, 110, 125 |
3. A group of experimenters determine that 3 factors seem to have the most influence on a coating process. The measure the out come Y in terms of coating thickness in some consistent way.
|
|
|
B - Catalyst |
|
|
|
|
|
|
0.1g/l |
0.2g/l |
|
|
|
|
C- Temperature |
C - Temperature |
|
||
|
|
15C |
25C |
15C |
25C |
|
|
A - Belt Rate |
19 |
21 |
21 |
20 |
|
|
400 mm/min |
17 |
20 |
19 |
18 |
|
|
Sum |
36 |
41 |
40 |
38 |
|
|
|
20 |
20 |
25 |
26 |
|
|
800 mm/min |
19 |
23 |
22 |
24 |
|
|
Sum |
39 |
43 |
47 |
50 |
|
|
|
|
|
|
|
|
· Which factors and interactions effects are significant?
4. In a 23 Full Factorial experiment to test the effects of cutting speed (A), Feed rate (B) and Hardness (C) on the surface finish. The data in Table 7 shows one observation per each of the 8 combinations.
i). Conduct ANOVA at α = 0.05 to test for the significance of all possible effects.
Table 7
Cutting Speed A
300RPM 350RPM
Hardness C
30 40 30 40
Feed Rate B
0.002 10 15 8 13
0.004 14 16 10 12
5. An engineer is interested in the effects of cutting speed (A), tool geometry (B), and cutting angle (C) on the life (in hours) of a machine tool. Two levels of each factor are chosen, and three replicates of a 23 factorial design are run. The results follow:
|
|
|
|
Treatment |
|
Replicate |
|
|
A |
B |
C |
Combination |
I |
II |
III |
|
- |
- |
- |
(1) |
22 |
31 |
25 |
|
+ |
- |
- |
a |
32 |
43 |
29 |
|
- |
+ |
- |
b |
35 |
34 |
50 |
|
+ |
+ |
- |
ab |
55 |
47 |
46 |
|
- |
- |
+ |
c |
44 |
45 |
38 |
|
+ |
- |
+ |
ac |
40 |
37 |
36 |
|
- |
+ |
+ |
bc |
60 |
50 |
54 |
|
+ |
+ |
+ |
abc |
39 |
41 |
47 |
· Estimate the factor effects. Which effects appear to be large?
3