Design & Factor Selection
Design Types & Categories
Johns 3/4 Designs - Johns 3/4 designs are 3/4 fractions of the regular Fractional Factorials For example, designs can be constructed of 12 runs (3/4 of 16 run) and 24 runs (3/4 of 32 runs). Conditions are chosen to maximize the number of interactions independently estimated. In this way, the designs are constrained by the interactions.
Usually, for the same number of runs, the Johns 3/4 designs can accommodate more interactions than a Placket-Burman or fractional factorial design.
Learn more about the DOE tools for designed experiments in Six Sigma Demystified (2011, McGraw-Hill) by Paul Keller, in his online Intro. to DOE short course (only $99) or online Advanced Topics in DOE short course (only $139), or his online Black Belt certification training course ($875).