Multi-level orthogonal arrays for estimating main effects and specified interactions

In some situations, the experimenter would like to study factors at more than two levels, such as when curvature has the potential to occur within the experimental region. In this paper we consider selecting orthogonal arrays with more than two levels, when there is a particular set of two-factor interaction components of interest to the experimenter. As designs with more than two levels have additional complications with level permutations, results are provided that aid in the search for efficient designs that have robust properties. We also examine the existence and construction of such designs through saturated orthogonal arrays.