The Modified Mixed Exponentially Weighted Moving Average-Cumulative Sum Control Charts for Autocorrelated Process

  • Dushyant Tyagi Dr. Shakuntala Misra National Rehabilitation University, Lucknow, India
  • Vipin Yadav Dr. Shakuntala Misra National Rehabilitation University, Lucknow, India https://orcid.org/0000-0002-5096-7418
Keywords: Statistical Process Control (SPC); Autocorrelation; Control Chart; Average Run Length (ARL); Modified Mixed EWMA-CUSUM

Abstract

Statistical Process Control (SPC) is an efficient methodology for monitoring, managing, analysing and recuperating process performance. Implementation of SPC in industries results in biggest benefits, as enhanced quality products and reduced process variation. While dealing with the theory of control chart we generally move with the assumption of independent process observation. But in practice usually, for most of the processes the observations are autocorrelated which degrades the ability of control chart application. The loss caused by autocorrelation can be obliterated by making modifications in the traditional control charts. The article presented here refers to a combination of EWMA and CUSUM charting techniques supplementing modifications in the control limits. The performance of the referred scheme is measured by comparing average run length (ARL) with existing control charts. Also, the referred scheme is found reasonably well for detecting particularly smaller displacements in the process.

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Author Biographies

Dushyant Tyagi, Dr. Shakuntala Misra National Rehabilitation University, Lucknow, India

Dushyant Tyagi has done his M.Sc., M.Phil. and Ph.D. (Statistics) from Department of Statistics, Ch. Charan Singh University, Meerut and possess Eleven years of experience of educating in various institutions of repute like G. B. Pant University of Agriculture and Technology, Institute of Technology and Science Ghaziabad, International College of Financial Planning, New Delhi and Lady Shri Ram College for Women, New Delhi. He is currently working as an Assistant Professor at the Department of Mathematics and Statistics, Faculty of Science and Technology, Dr. Shakuntala Misra National Rehabilitation University, Lucknow. His research area is Statistical Quality Control and Computational Statistics. He held the responsibility of Convener and resource person for three AICTE sponsored Faculty Development Program on Advance Data Analysis through Data Analysis Software’s. He delivered lectures in more than 25 research methodology workshops. He has six research paper publication in reputed International journals and one book. He has presented his research work in various National and International Conferences and attended several seminars and FDP’s of statistics and related areas.

Vipin Yadav, Dr. Shakuntala Misra National Rehabilitation University, Lucknow, India

Vipin Yadav has done his M.Sc. (GOLD MEDALIST) in Applied Statistics from the Department of Mathematics and Statistics at Dr. Shakuntala Misra National Rehabilitation University (DSMNRU) Lucknow in 2017. Qualified U.G.C. NET and J.R.F. and currently he is pursuing Ph.D. in Statistics from DSMNRU, Lucknow.

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Published
2021-10-06
Section
Articles