Box Behnken RSM: Difference between revisions

From ReliaWiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 109: Line 109:


::<math>\begin{align}
::<math>\begin{align}
Viscosity=-58.875+2.65×Temp-0.65×Agitation-11.125×Rate-0.0118×〖Temp〗^2+0.3×〖Agitation〗^2-0.145×〖Rate〗^2-0.032×Temp×Agitation+0.088×Temp×Rate+0.14×Agitation×Rate
Viscosity=-58.875+2.65 * Temp-0.65 * Agitation-11.125*Rate-0.0118*Temp^2+0.3*Agitation^2-0.145*Rate^2-0.032*Temp*Agitation+0.088*Temp*Rate+0.14*Agitation*Rate
\end{align}</math>
\end{align}</math>



Revision as of 23:27, 25 June 2015

DOE Reference Examples Banner.png


New format available! This reference is now available in a new format that offers faster page load, improved display for calculations and images and more targeted search.

As of January 2024, this Reliawiki page will not continue to be updated. Please update all links and bookmarks to the latest references at DOE examples and DOE reference examples.




Box Behnken RSM

This example validates the calculation of the Box-Behnken RSM method in DOE++.

Reference Case

Data is from Example 7.5 on page 347 in the book Response Surface Methodology, process and product optimization using design experiments, second edition, by Raymond H. Myers and Douglas C. Montgomery, John Wiley & Sons, Inc. 2002.

Data

Level (coded value) Temperature (A) Agitation (B) Rate
(C)
High (+1) 200 10 25
Center (0) 175 7.5 20
Low (-1) 150 5 15


Standard order A B C Y
1 -1 -1 0 53
2 +1 -1 0 58
3 -1 +1 0 59
4 +1 +1 0 56
5 -1 0 -1 64
6 +1 0 -1 45
7 -1 0 +1 35
8 +1 0 +1 60
9 0 -1 -1 59
10 0 +1 -1 64
11 0 -1 +1 53
12 0 +1 +1 65
13 0 0 0 65
14 0 0 0 59
15 0 0 0 62

The viscosity of the resin was recorded as an indirect measure of molecular weight.

Result

From the book, the ANOVA table (partial sum of squares) is:

Source Partial SS DF Mean Square F value Prob>F
Model 882.48 9 98.05 9.57 0.0114
A 8 1 8.00 0.78 0.4174
B 55.12 1 55.12 5.38 0.0681
C 45.13 1 45.13 4.40 0.09
〖 A〗^2 200.83 1 200.83 19.59 0.0069
B^2 12.98 1 12.98 1.27 0.3115
C^2 48.52 1 48.52 4.73 0.0816
AB 16.00 1 16.00 1.56 0.2668
AC 484.00 1 484.00 47.22 0.001
BC 12.25 1 12.25 1.22 0.3241
Residual 51.25 5 10.25
Lack of Fit 33.25 3 11.08 1.23 0.4774
Pure error 18 2 9.00
Cor total 933.73 14

The final equation in terms of actual factors:

[math]\displaystyle{ \begin{align} Viscosity=-58.875+2.65 * Temp-0.65 * Agitation-11.125*Rate-0.0118*Temp^2+0.3*Agitation^2-0.145*Rate^2-0.032*Temp*Agitation+0.088*Temp*Rate+0.14*Agitation*Rate \end{align} }[/math]


Results in DOE++

The software results match the book results. The ANOVA table is:

Behnken anova.png

The final equation in terms of actual factors is:

Behnken final.png

The maximum yield is achieved at 80.21, as shown in the optimization plot. The values at the red dash line are the optimal values for factor A and factor B. The blue line is corresponding to the maximum Y value.

Behnken plot.png