Often you do not have the resources for a full factorial design. In this case, a fractional factorial design is a reasonable alternative, provided that the effects of interest can be estimated. Box, ...

A fractional factorial DOE is a means of conducting ... or (400 rpm/800 rpm). In our coating example, we would call this design a 2-level, 3-factor full factorial DOE. The number of runs would ...

For example, if your output is the thickness ... Doing a full factorial as opposed to a fractional factorial or other ...