SKEDSOFT

Quality Control Engineering

Double Sampling Plan

A double sampling plan is a plan in which a maximum of two samples are checked before deciding upon the acceptability of the lot.

 

Acceptance-Rectification plan

An acceptance-rectification plan involves acceptance of goods on the basis of sampling and on the basis of 100 percent inspection, if sampling inspection does not accept. However all the goods dispatched by the producer will reach the consumer. Further the quality of goods reaching the consumer stores will be better than the goods originally shipped by the producer.

Terminology

Average Outgoing Quality (AOQ)

The average outgoing quality of an acceptance sampling plan is defined as the longrun average quality of goods that are accepted to the consumer stores. The AOQ of a sampling plan is given by AOQ = P Pa.

AOQ Curve : The AOQ Curve of an acceptance-rectification plan is plot of AOQ versus incoming lot quality.

Average Outgoing Quality Limit (AOQL)

The AOQL of an acceptance-rectification plan is defined as the AOQ that can occur irrespective of the value of incoming quality.

Average Total Inspection (ATI)

The ATI of acceptance-rectification plan is defined as the average amount of inspection effort that will occur with usage of such sampling plan. ATI for single sampling plan is given

ATI for double sampling plan