Construction of optimal fractional Order-of-Addition designs via block designs

Order of addition (OofA) experiments have found wide applications. Each order (run) of an OofA experiment is a permutation of m(≥2) components. It is typically infeasible to compare all the m! possible runs, especially when m is large. This calls for experimentation with a subset or fraction of these m! runs. However, only a few systematic results are available on the construction of such fractions ensuring optimality. We employ block designs to propose a systematic combinatorial construction method for optimal fractional OofA designs, and extend the method to construct highly efficient OofA designs, both in much smaller run sizes than the currently available optimal fractions.