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Moving Range and R Charts

  1. Charles W. Champ1,
  2. Deborah K. Shepherd2

Published Online: 15 MAR 2008

DOI: 10.1002/9780470061572.eqr250

Encyclopedia of Statistics in Quality and Reliability

Encyclopedia of Statistics in Quality and Reliability

How to Cite

Champ, C. W. and Shepherd, D. K. 2008. Moving Range and R Charts. Encyclopedia of Statistics in Quality and Reliability. III.

Author Information

  1. 1

    Georgia Southern University, Statesboro, GA, USA

  2. 2

    Louisiana State University, Shreveport, LA, USA

Publication History

  1. Published Online: 15 MAR 2008

Abstract

Control charts for controlling the process mean are affected by changes in the process standard deviation. Therefore it is important to also control the process standard deviation. Various control charting methods have been developed for this purpose. Two commonly recommended statistical methods for controlling the process standard deviation are the moving range (MR) and the range (R) charts. The designs of MR and R charts are discussed in this article and each is illustrated with an example.

Keywords:

  • Phase I;
  • Phase II;
  • cumulative sum;
  • dispersion;
  • quality control;
  • run length