Note that the ASS0 is
constrained to be a fixed sample size n of the Phase-I process for a
commensurate single sampling (SS) plan. Additionally, the
selection of the first and second optimal sample sizes (n1, n2) is
restricted by the constraint 1 6 n1 < n < n1 + n2. Since the optimal
MRL-based DS X chart with known parameters is currently not
available, for completeness, this optimal chart is proposed in this
paper as well.