Abstract
The quality of products produced and services provided can only be improved by examining the process to identify causes of variation. Modern production processes can involve tens to hundreds of variables, and multivariate procedures play an essential role when evaluating their stability and the amount of variation produced by common causes. Our treatment emphasizes the detection of a change in level of a multivariate process.
After a brief introduction, in Sect. 18.1 we review several of the important univariate procedures for detecting a change in level among a sequence of independent random variables. These include Shewhartʼs X −bar chart, Pageʼs cumulative sum, Crosierʼs cumulative sum, and exponentially weighted moving-average schemes.
Multivariate schemes are examined in Sect. 18.2. In particular, we consider the multivariate T 2 chart and the related bivariate ellipse format chart, the cumulative sum of T chart, Crosierʼs multivariate scheme, and multivariate exponentially weighted moving-average schemes.
An application to a sheet metal assembly process is discussed in Sect. 18.3 and the various multivariate procedures are illustrated.
Comparisons are made between the various multivariate quality monitoring schemes in Sect. 18.4. A small simulation study compares average run lengths of the different procedures under some selected persistent shifts.
When the number of variables is large, it is often useful to base the monitoring procedures on principal components. Section 18.5 discussesthis approach. An example is also given using the sheet metal assembly data.
Finally, in Sect. 18.6, we warn against using the standard monitoring procedures without first checking for independence among the observations. Some calculations, involving first-order autoregressive dependence, demonstrate that dependence causes a substantial deviation from the nominal average run length.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- ARL:
-
average run length
References
W. A. Shewhart: Economic Control of Quality of Manufactured Product (Van Nostrand, New York 1931)
E. S. Page: Continuous inspection schemes, Biometrika 41, 100–115 (1954)
R. B. Crosier: A new two-sided cumulative sum quality control scheme, Technometrics 28, 187–194 (1986)
J. M. Lucas, M. S. Saccucci: Exponentially weighted moving average control schemes: properties and enhancements, Technometrics 32, 1–12 (1990)
D. C. Montgomery: Introduction to Statistical Quality Control, 4th edn. (Wiley, New York 2000)
Li, R. New Multivariate Schemes for Statistical Process Control, Dissertation, Department of Statistics, Univ. of Wisconsin (2004)
J. E. Jackson: Quality control methods for several related variables, Technometrics 1, 359–377 (1959)
J. E. Jackson: Multivariate quality control, Commun. Stat. A 14, 2657–2688 (1985)
N. Doganaksoy, J. Fulton, W. T. Tucker: Identification of out of control quality characteristics in multivariate manufacturing environment, Commun. Stat. A 20, 2775–2790 (1991)
N. D. Tracy, J. C. Young, R. L. Mason: Multivariate quality control charts for individual observations, J. Qual. Technol. 24, 88–95 (1992)
R. B. Crosier: Multivariate generalizations of cumulative sum quality-control schemes, Technometrics 30, 291–303 (1988)
C. Fuchs, R. S. Kenett: Multivariate Quality Control: Theory and Applications (Marcel Dekker, New York 1998)
K. Yang, J. Trewn: Multivariate Statistical Methods in Quality Management (McGraw-Hill, New York 2004)
R. A. Johnson, D. W. Wichern: Applied Multivariate Statistical Analysis (Prentice Hall, Piscataway 2002)
C. A. Lowry, W. H. Woodall, C. W. Champ, S. E. Rigdon: A multivariate exponentially weighted moving average control chart, Technometrics 34, 46–53 (1992)
D. Ceglarek, J. Shi: Dimensional variation reduction for automotive body assembly, Manuf. Rev. 8, 139–154 (1995)
J. J. Pignatiello, G. C. Runger: Comparisons of multivariate CUSUM charts, J. Qual. Technol. 22, 173–186 (1990)
C. A. Lowry, D. C. Montgomery: A review of multivariate control charts, IIE Trans. 27, 800–810 (1995)
T. Kourti, J. F. MacGregor: Multivariate SPC methods for process and product monitoring, J. Qual. Technol. 28, 409–428 (1996)
R. A. Johnson, T. Langeland: A linear combinations test for detecting serial correlation in multivariate samples. In: Statistical Dependence, Topics, ed. by H. Block et al. (Inst. Math. Stat. Mon. 1991) pp. 299–313
R. A. Johnson, M. Bagshaw: The effect of serial correlation on the performance of CUSUM tests, Technometrics 16, 103–112 (1974)
M. Bagshaw, R. A. Johnson: Sequential procedures for detecting parameter changes in a time-series model, J. Am. Stat. Assoc. 72, 593–597 (1977)
D. M. Hawkins, D. Olwell: Cumulative Sum Charts and Charting for Quality Improvement (Springer, New York 1998)
Author information
Authors and Affiliations
Corresponding authors
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2006 Springer-Verlag
About this entry
Cite this entry
Johnson, R., Li, R. (2006). Multivariate Statistical Process Control Schemes for Controlling a Mean. In: Pham, H. (eds) Springer Handbook of Engineering Statistics. Springer Handbooks. Springer, London. https://doi.org/10.1007/978-1-84628-288-1_18
Download citation
DOI: https://doi.org/10.1007/978-1-84628-288-1_18
Publisher Name: Springer, London
Print ISBN: 978-1-85233-806-0
Online ISBN: 978-1-84628-288-1
eBook Packages: EngineeringEngineering (R0)