  Subject of this paper is ASN-Minimax (AM) double sampling plans by variables
for a normally distributed quality characteristic with unknown standard
deviation and two-sided specification limits. Based on the estimator p* of the
fraction defective p, which is essentially the Maximum-Likelihood (ML)
estimator, AM-double sampling plans are calculated by using the random
variables p*_1 and p*_p relating to the first and pooled samples, respectively.
Given p_1, p_2, {\alpha}, and {\beta}, no other AM-double sampling plans based
on the same estimator feature a lower maximum of the average sample number
(ASN) while fulfilling the classical two-point condition on the corresponding
operation characteristic (OC).
