6. Conclusions
Acceptance sampling is a statistical procedure used for determining
whether to accept or reject a production lot of material.
It has been a common quality control technique used in industry
and particularly the military for contracts and procurement. Due
to the sampling cannot guarantee that every defective item in a
lot will be inspected, the sampling involves risks of not adequately
reflecting the quality conditions of the lot. Such risk is even more
significant as the rapid advancement of the manufacturing technology
and stringent customers demand is enforced. In particular,
when the fraction of nonconforming products is required very low,
such as measured in PPM, the required number of inspection items
must be very large in order to adequately reflecting the actual lot
quality. This paper developed a variables inspection scheme for
resubmitted lots based on the commonly used capability index
Cpk to deal with the product acceptance decision making problem,
especially for situations with very low fraction of defectives. The
proposed variables resubmitted sampling plan is developed based
on the exact sampling distribution rather than an approximation
approach. The performance of the proposed variables resubmitted
sampling plan is examined and it will reduce to the existing variables
single sampling plan if m = 1. The results show that the
developed resubmitted sampling plan has a better OC curve than
the variables single sampling plan at good quality levels and also
ensures protection against the consumer point of view at poor