Transcript Thickness
Descriptive Analysis Using Minitab
Slide 1
S/N Ratio
Slide 2
Note
The Nominal is Best (default) S/N ratio
is good for analyzing or identifying
scaling factors, which are factors in
which the mean and standard
deviation vary proportionally. Scaling
factors can be used to adjust the mean
on target without affecting S/N ratios.
Slide 3
Larger the better
(golf ball case)
You manufacture golf balls and are working on a
new design to maximize ball flight distance. You
have identified four control factors, each with two
levels:
Core material (liquid vs. tungsten)
Core diameter (118 vs. 156)
Number of dimples (392 vs. 422)
Cover thickness (.03 vs. .06)
You also want to test the interaction between core
material and core diameter.
Slide 4
The response is ball flight distance in
feet. The noise factor is two types of
golf clubs: driver and a 5-iron. You
measure distance for each club type,
resulting in two noise factor columns in
the worksheet. Because your goal is to
maximize flight distance, you select
the larger-is-better signal-to-noise
(S/N) ratio .
Slide 5
1 Open the worksheet GOLFBALL.MTW. The design and
response data have been saved for you.
2 Choose Stat > DOE > Taguchi > Analyze Taguchi
Design.
3 In Response data are in, enter Driver and Iron.
4 Click Analysis.
5 Under Fit linear model for, check Signal-to-noise ratios
and Means. Click OK.
6 Click Terms.
7 Move the term AB to Selected Terms by using the arrow
keys or double-clicking it. Click OK.
8 Click Options.
9 Under Signal to Noise Ratio, choose Larger is better.
Click OK in each dialog box.
Slide 6
Data
Material
Diameter
Dimples
Thickness
Driver
Iron
(KOLOM A)
(KOLOM B)
(KOLOM D)
(KOLOM E)
(Ulangan 1)
(Ulangan 2)
Liquid
118
392
0.03
247.5
234.3
Liquid
118
422
0.06
224.4
214.5
Liquid
156
392
0.03
59.4
49.5
Liquid
156
422
0.06
75.9
72.6
Tungsten
118
392
0.06
155.1
148.5
Tungsten
118
422
0.03
39.6
29.7
Tungsten
156
392
0.06
92.4
82.5
Tungsten
156
422
0.03
21.9
18.6
Slide 7
Slide 8
Main Effects Plot (data means) for SN ratios
Material
Diameter
42
40
Mean of SN ratios
38
36
34
Liquid
Tungsten
118
Dimples
156
Thickness
42
40
38
36
34
392
422
0.03
0.06
Signal-to-noise: Larger is better
Slide 9
Interaction Plot (data means) for SN ratios
118
156
48
44
Material
Liquid
Tungsten
40
Material
36
32
48
Diameter
118
156
44
40
Diameter
36
32
Liquid
Tungsten
Signal-to-noise: Larger is better
Slide 10
For this example, because your goal is to increase ball flight
distance, you want factor levels that produce the highest mean. In
Taguchi experiments, you always want to maximize the S/N ratio.
The level averages in the response tables show that the S/N ratios
and the means were maximized when the core was liquid, the core
diameter was 118, there were 392 dimples, and the cover thickness
was .06. Examining the main effects plots and interaction plots
confirms these results. The interaction plot shows that, with the
liquid core, the flight distance is maximized when the core diameter
is 118.
Based on these results, you should set the factors at:
Material
Diameter
Dimples
Thickness
Liquid
118
392
.06
Slide 11
Predicted values :
S/N Ratio
53.6844
Mean
276.263
Factor levels for predictions
Material
Liquid
Diameter
118
Dimples
392
Thickness
0.06
Interpreting the results
For the factor settings you selected, the S/N ratio is predicted to be
53.6844 and the mean (the average ball flight distance) is predicted
to be 276 yards. Next, you might run an experiment using these
factor settings to test the accuracy of the model.
Slide 12
Slide 13
Interpreting the Results Predicting Results
The predicted results for the chosen factor settings
are: S/N ratio of 33.8551, mean of 17.5889, and
standard deviation of 0.439978. Next, you might run
an experiment using these factor settings to test the
accuracy of the model
The predicted values for the standard deviation and
log of the standard deviation use different models of
the data.
Slide 14
Latihan
Diketahui karakteristik kualitas bersifat
larger-the-better. Respon adalah pulloff force yang akan dimaksimumkan.
Buatkan grafik respon dari SN ratio
untuk keempat factor yang dicobakan
serta tentukan nilai prediksi SN.
Slide 15
Factors and Levels for Tube
Control Factors
Levels
A. Interference
Low
Med
High
B. Wall Thickness
Thin
Med
Thick
C. Insertion Depth
Shal.
Med
High
D. % adhesive
Low
Med
High
Noise Factors
Levels
E. Time
24 h
120 h
F. Temp
72F
150F
G. RH
25%
75%
Slide 16
Control Factors
Treatment
Combinati
on
A
B
Noise
C
D
E1F1G1
E1F2G2
E2F1G2
E2F2G1
1(A1B1C
1D1)
1
1
1
1
15.6
19.9
19.6
20
2(A1B2C
2D2)
1
2
2
2
15
19.6
19.8
24.2
3
1
3
3
3
16.3
15.6
18.2
23.3
4
2
1
2
3
18.3
18.6
18.9
23.2
5
2
2
3
1
19.7
25.1
21.4
27.5
6
2
3
1
2
16.2
19.8
19.6
22.5
7
3
1
3
2
16.4
23.6
18.6
24.3
8
3
2
1
3
14.2
16.8
19.6
23.3
9
3
3
2
1
16.1
17.3
22.7
22.6
Slide 17