How to Maintain Your Confidence
Setting test limits different than specification limits influences the risk of accepting defective units (consumer risk) and rejecting conforming units (producer risk). Much has been written about setting limits to accomplish various strategies such as maintaining a minimum consumer risk, equalizing consumer risk with producer risk, minimizing total risk, or equalizing the cost of faulty test decisions between the producer and consumer.
This paper reviews the statistical foundation for making decisions as to where to place test limits and includes a multitude of charts to simplify what used to be tedious calculations of the test limit, consumer risk, and producer risk. The implications of various test strategies can be seen very quickly using the charts.