Question: In Case Study 15.2 involving the
In Case Study 15.2 involving the coal cleansing data, the percent solids in the process system is known to vary uncontrollably during the process and is viewed as a noise factor with mean 0 and varianceσ2z . The response, cleansing efficiency, has a mean and variance that change behavior during the process. Use only significant terms in the following parts.
(a) Use the estimates in Figure 15.9 to develop the process mean efficiency and variance models.
(b) What factor (or factors) might be controlled at certain levels to control or otherwise minimize the process variance?
(c) What conditions of factors B and C within the design region maximize the estimated mean?
(d) What level of C would you suggest for minimization of process variance when B = 1? When B = −1?
Figure 15.9:
Transcribed Image Text:
Solder Pot Temperature Flux Density 250 250 185 185 120 120 Low High Low High (-1) (+1) (-1) (+1) Figure 15.19: Plot showing the influence of factors on the mean response. Mean,y Mean,y
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