Selecting the Right Central Composite Design

Comparative studies of five varieties of Central Composite design (SCCD, RCCD, OCCD, Slope-R, FCC) in Response Surface Methodology (RSM) were evaluated using the D, A, G and IV-optimality criteria. The fraction of design space plot of these designs was also displayed. The basis of variation in these designs is distance of the axial points from the center of the design. These axial portions of these designs were also replicated. The results show that replicating the star points tends to reduce the D and G-optimality criteria of the CCDs (SCCD, RCCD, OCCD, Slope-R, and FCC) in all the factors that were considered while it is not so for A-optimality criterion. In IV-optimality, the CCDs are relatively the same both when the center points and axial portion are increased. The FDS plots indicates that the CCDs maintain relatively low and stable SPV when the star points are replicated with increased center points.