Six Sigma Case Studies with Minitab®

152 Six Sigma Case Studies with Minitab

®

FIGURE 9.28

Selection of “Simplex lattice”.

FIGURE 9.29

Entry of “Degree of lattice”.

153Mixture Designs to Optimize Pollution Level and Temperature of Fuels

Select “Temperature” for “Responses” and click on “Terms”. This opens the

dialog box shown in Figure9.38. Choose “Quadratic” for “Include component

terms for model” and choose the “Selected Terms” as shown in Figure9.38.

Click on “OK” and it takes you back to the dialog box shown in Figure9.37.

Click on “OK” and the output shown in Figure9.39 is the result. Notice that

all the P-values in Figure9.39 are less than 0.05, and hence this model in

Figure9.39 can be considered now for optimization. For optimization of tem-

perature, select “Response Optimizer” as shown in Figure 9.40. Doing so

opens the dialog box shown in Figure9.41. Move the “Temperature” column

from “Available” to “Selected”, as shown in Figure9.42. Click on “Setup” and

FIGURE 9.30

Entry of lower and upper bounds for components of fuel Zeo.

FIGURE 9.31

Unchecking “Randomize runs” box for fuel Zeo.

154 Six Sigma Case Studies with Minitab

®

FIGURE 9.32

Partial mixture design for fuel Zeo.

FIGURE 9.33

Options for “Simplex Design Plot” for fuel Zeo.

155Mixture Designs to Optimize Pollution Level and Temperature of Fuels

X

20

60

Y

60

20

Z

60

20

Simplex Design Plot in Amounts

FIGURE 9.34

“Simplex Design Plot” for fuel Zeo.

FIGURE 9.35

Mixture design for fuel Zeo.

156 Six Sigma Case Studies with Minitab

®

FIGURE 9.36

Selection of “Analyze Mixture Design” for fuel Zeo.

FIGURE 9.37

Selection of “Temperature” column for “Responses”.