Synthetic-type control charts for monitoring general inflated poisson processes

Abstract

The statistical monitoring of count data has received much attention in the recent years, with applications in several areas of applied research. The basic tool for monitoring an integer-valued process is the Shewhart control chart. In this work we investigate the performance of two Synthetic-type charts in the monitoring of a general inflated Poisson process. Synthetic charts are considered as viable alternatives to Shewhart charts, when we are interested in detecting quickly small and moderate shifts in the process parameters. Moreover, they retain the simplicity in design, operation, and interpretation of the Shewhart chart. We present the results of a numerical study regarding the statistical design and the performance of the proposed Synthetic charts. Finally, we provide two real-data examples that demonstrate the implementation of the proposed charts.

Keywords:

• Conforming run-length (CRL) chart
• Expected average run length
• Shewhart chart
• Statistical process control
• Steady-state average run length
• Zero-state average run length

Acknowledgments

The authors would like to thank the anonymous reviewer for his/her constructive comments which improved the content and the presentation of this paper. The second author would like to express his gratitude to the University of the Aegean, where this research was completed, when he was affiliated with it.