Department of Industrial Engineering, Yazd University, Yazd, P.O. Box 89195-741, Iran.
Nowadays, continuous improvement can be regarded as the essence of survival and growth in order to not only increase the competition in global market, but also requirement for ever-decreasing defect levels in processes. Therefore, new statistical analysis techniques and decision-making procedures have been continuously evolved, both to handle high quality processes and to look for process improvement opportunities. CCC-r chart, or extended approach of CCC charts, is generally a technique for high quality processes, when nonconforming items are rarely observed. This study develops a mathematical model based on the average number of inspected items for the economic design of CCC-r chart, so that the average cost per item is minimized. The optimal designed parameters for dierent nonconforming fractions and dierent parameters in each iteration are calculated. In addition, with respect to Type I error () and Type II error () in the process, sensitivity analysis of the model is carried out.