Cost effectiveness of using a correlated variable in a complete inspection plan when inspection error is present

Due to advances in automated manufacturing systems and automatic inspection equipment, complete inspection (screening) has drawn increased attention recently and has become a widespread practice. Screening can be based on the performance variable of interest or on a variable which is correlated with the performance variable. Using a correlated variable as the screening variable is attractive when the inspection on the performance variable is destructive or costely. The purpose of this article is to illustrate both theoretically and empirically when a correlated variable rather than the performance variable should be used as the screening variable when inspection error is present.