A Flexible Statistical Control Chart for Dispersed Count Data

The Poisson distribution is a popular distribution used to describe count information, from which control charts involving count data have been established. Several works recognize the need for a flexible control chart to allow for data over-dispersion; however, analogous arguments can also be made to account for potential under-dispersion. The Conway–Maxwell–Poisson (COM-Poisson) distribution is a general count distribution that relaxes the equi-dispersion assumption of the Poisson distribution and, in fact, encompasses the special cases of the Poisson, geometric, and Bernoulli distributions. This talk introduces the resulting flexible control chart that encompasses the classical Shewart charts based on the Poisson, Bernoulli (or binomial), and geometric (or negative binomial) distributions, and discusses resulting developments based on this work.

Presentation Slides: PPT

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