EWMA Chart and Measurement Error

Measurement error is a usually met distortion factor in real-world applications that influences the outcome of a process. In this paper, we examine the effect of measurement error on the ability of the EWMA control chart to detect out-of-control situations. The model used is the one involving linear covariates. We investigate the ability of the EWMA chart in the case of a shift in mean. The effect of taking multiple measurements on each sampled unit and the case of linearly increasing variance are also examined. We prove that, in the case of measurement error, the performance of the chart regarding the mean is significantly affected.

[1]  H. Mittag,et al.  Gauge imprecision effect on the performance of the X-S control chart , 1998 .

[2]  Charles W. Champ,et al.  A a comparison of the markov chain and the integral equation approaches for evaluating the run length distribution of quality control charts , 1991 .

[3]  Douglas C. Montgomery,et al.  GAUGE CAPABILITY AND DESIGNED EXPERIMENTS. PART I: BASIC METHODS , 1993 .

[4]  James M. Lucas,et al.  Exponentially weighted moving average control schemes: Properties and enhancements , 1990 .

[5]  Connie M. Borror,et al.  Robustness of the EWMA Control Chart to Non-Normality , 1999 .

[6]  Fah Fatt Gan,et al.  Designs of One- and Two-Sided Exponential EWMA Charts , 1998 .

[7]  Rickie J. Domangue,et al.  Some omnibus exponentially weighted moving average statistical process monitoring schemes , 1991 .

[8]  Zachary G. Stoumbos,et al.  Robustness to Non-Normality of the Multivariate EWMA Control Chart , 2002 .

[9]  S. Steiner.  EWMA Control Charts with Time-Varying Control Limits and Fast Initial Response , 1999 .

[10]  K. E. Case,et al.  Development and Evaluation of Control Charts Using Exponentially Weighted Moving Averages , 1989 .

[11]  William H. Woodall,et al.  Effect of Measurement Error on Shewhart Control Charts , 2001 .

[12]  S. Crowder.  A simple method for studying run-length distribution of exponentially weighted moving average charts , 1987 .

[13]  W. Woodall,et al.  The Performance of Multivariate Control Charts in the Presence of Measurement Error , 2001 .

[14]  Marion R. Reynolds,et al.  Shewhart and EWMA Variable Sampling Interval Control Charts with Sampling at Fixed Times , 1996 .

[15]  G. Robin Henderson,et al.  EWMA and industrial applications to feedback adjustment and control , 2001 .