A new X chart comparable to CUSUM and EWMA charts
by D.R. Prajapati, P.B. Mahapatra
International Journal of Productivity and Quality Management (IJPQM), Vol. 4, No. 1, 2009

Abstract: The most popular and efficient charts to catch small shifts in process mean are CUSUM and EWMA charts. However, they catch the shift on process average if there is a single and sustained shift, and are unable to detect the changes when samples are not taken from same stream. In such situation, the new chart is proposed in the present work and compared with conventional CUSUM and EWMA charts. It is found that both CUSUM and EWMA schemes are ineffective to catch the process shifts in such cases. It can be noted that the new (proposed) chart provides the highest percentage of correct signals compared to CUSUM and EWMA schemes for all process shifts. It is also clear from the study that for all the process shifts, the EWMA scheme is most ineffective out of the three schemes. The average run length (ARLs) of proposed scheme is much lower than both CUSUM and EWMA schemes for all the shifts in the process average.

Online publication date: Sun, 07-Dec-2008

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Productivity and Quality Management (IJPQM):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com