The design of blocked fractional factorial split-plot experiments

In industrial screening experiments, if some factors are hard to vary and others are easy to vary, randomization restrictions may lead to the use of fractional factorial split-plot (FFSP) designs. Blocked FFSP (BFFSP) designs arise when all runs cannot be performed under homogeneous conditions. This article introduces three approaches for blocking FFSP designs. A catalog of designs is presented in which BFFSP designs are ranked according to the minimum aberration criterion. In addition, additional optimality criteria are used to assist in the ranking procedure. The case study that motivated this research is also discussed in detail.