Synthetic-np chart for attributes

Abstract

While the np chart is powerful for detecting large shifts in fraction nonconforming p, the synthetic chart is more effective for detecting small p shifts. In this article, the salient features of the np chart and synthetic chart are hybridized to produce the Syn-np chart. The results of the performance studies indicate that the new Syn-np chart significantly outperforms the np chart and synthetic chart by 73% and 31%, respectively, in terms of Average Number of Defectives (AND) across a wide range of p shifts under different circumstances. Keywords -Syn-np chart, synthetic chart, np chart, average number of defective978-1-4577-0739-1/11/$26.00 ©2011 IEEE