A conservative adjustment to the ETSS procedure

Two-stage selection procedures have been widely studied and applied in determining the required sample size (i.e., the number of replications or batches) for selecting the best of k designs. The enhanced two-stage selection (ETSS) procedure is a heuristic two-stage selection procedure that takes into account not only the variance of samples, but also the difference of sample means when determining the sample sizes. This paper discusses the use of a conservative adjustment with the ETSS procedure to increase the probability of correct selection. We show how the adjustment allocates more simulation replications or batches to more promising designs at the second stage. An experimental performance evaluation demonstrates the efficiency of the adjustment.