In this section, we discuss the optimal split-plot schemes of 12-, 16-, 20- and 24-run two-level
factorial designs under the MGA criterion. We focus only on the factorial split-plot designs with
resolution III or higher, that is, the factorial split-plot designs whose WP and SP factors form an OA.
A factorial split-plot design with m1 WP factors and m2 SP factors can be constructed from an OA
with m = m1 + m2 columns according to Rule 1. Note that the number of columns generated in