Design & Factor Selection
Design Types & Categories
Mixed level design experiments have factors in which at least one factor has a count of levels which is different than another factor. For example, a 2-factor design in which one factor has 2 levels and another has 3 levels is a mixed level design; so is a design consisting of a 2-level factor, a 3-level factor and a 12 level factor. Mixed level design experiments are generated using Pseudo-factors
To determine the number of runs required to estimate each possible factor and interaction in a mixed-level design, multiply the number of runs calculated separately for each fixed-level case. For example, a design with five two-level factors and one three-level factor would require 25 x 31 = 32 x 3 = 96 runs. See Factorial Designs
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).