In an experiment, one or more process variables (or factors)
should be changed intentionally so that the effect of the changes
on one or more response variables could be monitored. The design
of experiments (DOE) is an effective way in order to analyze the
obtained data and produce valid and objective conclusions (NIST
ITL, 2012) with a minimum number of experiments.
The variables selected to be changed in this research are as
follows: