Modeling and Multivariate Methods - SAS

Chapter 24 Visualizing, Optimizing, and Simulating Response Surfaces 605
The Simulator
For the orange curve, USL Chop, there are good opportunities. Reading the curve from the right, the curve
starts out at the current defect rate (0.03), then as you start rejecting more parts by decreasing the USL for
SULFUR, the defect rate improves. However, moving a spec limit to the center is equivalent to throwing
away half the parts, which may not be a practical solution.
Looking at all the opportunities over all the factors, it now looks like there are two good options for a first
move: change the mean of SILICA to about 1, or reduce the variation in SULFUR. Since it is generally easier
in practice to change a process mean than process variation, the best first move is to change the mean of
SILICA to 1.
Figure 24.55 Adjusting the Mean of Silica
After changing the mean of SILICA, all the defect curves become invalid and need to be rerun. After clicking
Rerun, we get a new perspective on defect rates.
Figure 24.56 Adjusted Defect Rates