On the optimality of orthogonal array plus one run plans

Abstract

Much contrary to popular belief and even a published result, it is seen that orthogonal array plus one run plans are not necessarily optimal, within the relevant class, for general $s_1 \times \dots \times s_m$ factorials. A broad sufficient condition on $s_1,\dots, s_m$ ensuring the optimality of such plans has been worked out. This condition covers, in particular, all symmetric factorials and thus strengthens some previous results.