Development of multi stage multiple sampling plans for variable quality characteristics

Abstract

The main advantages of variable sampling plans are the existence of a small sample size for effective decisions and receiving good information on the quality characteristics. But small samples sometimes may lead to wrong decisions during the inspection of the lot and can increase the risk of the producer or consumer. The same scenario may happen in the double or triple sampling also due to small sample sizes. The quality control professionals suggest multiple sampling inspections when the size of the lot is very large. Hence an attempt has been made to design and develop new multi stage multiple sampling plans for variable quality characteristics with unknown standard deviation. These plans are useful for quality characteristic that are measured in a continuous scale for sentencing the large lot. The efficiency measures of the sampling plan are derived and the designing methodology is presented. Tables are constructed for the selection of parameters of multiple sampling plans through standard quality levels.