|
Articles
|
|
|
QICID: 19723
Title: The Changepoint Model for Statistical Process Control
Copyright: 2003, ASQ
Author: Hawkins, Douglas M.; Qiu, Peihua
Organization: University of Minnesota, Minneapolis, MN; Hanyang University, Seoul, Korea
Subject: Statistical process control (SPC),Unknown parameters,Special causes,Exponentially weighted moving average control charts (EWMA),Shewhart control chart,Cumulative sum control chart (CUSUM);
Series: Journal of Quality Technology, Vol. 35, No. 4, October 2003, pp. 355-366
This ARTICLE is available FREE
to all readers.
Abstract: [This abstract is based on the authors' abstract.]Standard statistical process control (SPC) methods require that the in-control values of the process parameters be known with accuracy in order to detect changes in the pattern of data. When using estimated parameters, random changes make it impossible to control the run length behavior of any particular chart. The unknown-parameter changepoint formulation is an effective Phase I analysis tool for detecting and diagnosing step changes based on imperfect process knowledge. Its performance is similar to that of the optimal cumulative sum chart that requires specification of the post-change process parameter values. Additionally, the changepoint formulation is comparable to the Shewhart chart for isolated non-sustained special causes.
Browse QIC articles chronologically
previous next
|
|
