An economic off-line quality control approach for unstable production processes

An economic off-line inspection/disposition approach is proposed, which incorporates manufacturing variation. This approach includes a new inspection algorithm for inspections based on cost minimization and utilizing a specified confidence level for identifying in-control items. This approach addresses two situations not addressed in previous papers: (i) the last unit in the batch is conforming; (ii) inspection time is non-negligible. Advantages are that there is no need to record the original position of each unit, the impact of manufacturing variation is reduced and non-negligible inspection times can be easily incorporated. Comparisons of this approach to other approaches are provided.