Economic Selection of Specification Limits for a Given Target Value

공정평균(工程平均)의 목표치(目標値)가 주어진 경우 규격한계(規格限界)의 경제적(經濟的) 선정(選定)

An Economic selection of specification limits is considered for a given target value in a complete inspection plan. Each item is inspected, and if it meets the specification, it is accepted. Items less than the lower specification limit are scrapped or sold at a reduced price, and those greater than the upper specification limit are reworked. Cost factors to be considered are economic loss caused by quality deviations, rework cost and scrapping cost. Methods for finding the optimal specification limits are given for the cases of piecewise linear loss function and quadratic loss function with illustrative examples.