Design Of Sampling Plan In Terms Of Acceptable Quality Level (AQL) And Sustainable Quality Region (SQR)

ABSTRACT

Attribute sampling plans on quality indices like AQL and MAPD gives the way for Sustainable Quality Region especially for the product at initial stage of production, where the exact quality of the product was not well designed. Optimum information on Acceptable quality level (AQL) and Maximum allowable percent defective would be better for protecting both consumer and producer in terms of SQR along with AQL or MAPD. New single sampling plans were developed by suggesting a unique monotonic increasing function on operating ratio(R) based on SQR with either AQL or MAPD corresponding to acceptance numbers. This study suggests a new quality region called Sustainable Quality Region (SQR) which exceed AQL and precede MAPD. ie proportional defective falls between AQL and MAPD ( SQR ), ie SQR= ( MAPD-AQL). Also, optimum sampling plan was suggested by establishing the measures AQL and MAPD, which are more producer and consumer friendly. The OC curves of SQR plans were compared with other AQL plans. Another single sampling plan was developed by considering the relationship between the MAPD with SQR so as to obtain the quality level that will protect consumer from getting the product with poor quality. Also economic SSP was developed based on MAPD –Min(ATI) at AQL and SQRMin(ATI) at MAPD which aims for developing the quality level that both consumer and producer will be protected from getting poor quality product (consumer‘s risk) with minimal cost of inspection as well as high quality items not to be rejected (producer‘s risk). Also interesting relationships of SQR with AQL, MAPD, LTPD, TQR, AOQL and MAAOQ were presented so as to evaluate the other quality indices of the prescribed and suitable examples were illustrated.