SOME ALTERNATIVES TO DOUBLE SAMPLING FOR PRODUCT CONTROL.

As alternatives to usual double sampling, lot-by-lot acceptance sampling procedures are proposed here. In these schemes, whenever a second sample is needed, the sample information from neighbouring lots is used. The procedures are applicable for attributes as well as for variables such as known and unknown sigma plans. They are also applicable when the acceptance criterion is the variance. These plans have operating characteristic curves identical to that of comparable double sampling plans under a set of mild conditions. The primary advantage of these plans is a reduction in cost due to a smaller average sample number