6.4 Consider the wave soldering problem in Example 6.4.

(a) Analyse the data by separately minimizing log ????y, log ????v, and log ????y and maximizing log ????v. Are there any contradictory conclusions on the optimal factor settings?

(b) Analyse the data by separately solving the smaller-the-better problem of the lower limit and the larger-the-better problem of the upper limit. Are there any contradictions in the conclusions?

(c) Compare the two solutions with separate objective functions with the one in Example 6.4.

(d) The operating window turned out to be [235.7◦; 251.7◦], but only factors D, H, and J were considered. Even if the other factors are statistically insignificant for the window width, they may be significant for the window position. Estimate the window width with this in mind.

(e) The window [235.7◦; 251.7◦] was obtained using only the point estimates of the means and standard deviations. What will this window be if the uncertainties of these estimates are taken into account?