A new X chart comparable to CUSUM and EWMA charts

D.R. Prajapati and P.B. Mahapatra

International Journal of Productivity and Quality Management, 2009, vol. 4, issue 1, 103-128

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.

Keywords: average run length; ARL; chi-squares; x-bar charts; CUSUM; EWMA; correct signalling; control charts; SPC; statistical process control. (search for similar items in EconPapers)
Date: 2009
References: Add references at CitEc
Citations:

Downloads: (external link)
http://www.inderscience.com/link.php?id=21873 (text/html)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:ids:ijpqma:v:4:y:2009:i:1:p:103-128

Access Statistics for this article

More articles in International Journal of Productivity and Quality Management from Inderscience Enterprises Ltd
Bibliographic data for series maintained by Sarah Parker ().