A double generally weighted moving average control chart for monitoring zero-inflated Poisson processes

Abstract.

The zero-inflated Poisson (ZIP) distribution is used to model count data with an excessive number of zeros. In this article, we present a double generally weighted moving average control chart for monitoring ZIP processes (regarded as ZIP-DGWMA chart). The run-length distribution of the proposed chart is evaluated by performing Monte Carlo simulations. A comparison study with the ZIP-GWMA chart indicates that the ZIP-DGWMA chart is more effective for shifts in the zero-inflated parameter p and for small shifts in both of the zero-inflated and Poisson parameters. The proposed chart is also applied on an example to demonstrate its application.

Keywords:

• Average run-length
• DGWMA chart
• GWMA chart
• Monte Carlo simulations
• zero-inflated Poisson distribution

Acknowledgments

The authors would like to thank the editor and the referees for their useful comments, which resulted in improving the quality of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).