Full factorial designs

FF designs form the basis for all classical designs, both screening and RSM.
• We start with FF designs
• FF.s rarely used in practice (too many runs)
• Rather fractional factorials
(FrF) and related designs are
the most used.
• To understand and use the
latter (FrF), however, we need
to understand the FF designsFor screening, FF is mostly used
two level FF designs allows every level of factor is investigated at low and high level of other factors.
example of 2 factors, and one center point

interaction between 2 factors shown: x1*x2, the number of regression coefficient =1
example of 3 factors,


the number of regression coefficient = 6

how regression coefficient is calculated



in Design of experiment (DOE) all factors are varied together.




the Effect is encoded by regression coefficient.