Development of a Repetitive Control Chart for Monitoring Processes with Dagum-Distributed Data

This paper presents a repetitive control chart designed for monitoring processes where the quality characteristic follows a Dagum distribution a flexible, skewed distribution often used in income, finance, and reliability data. Traditional control charts assume normality, resulting in poor performance with heavy-tailed or skewed distributions. To address this, we introduce a repetitive control chart based on quantiles of the Dagum distribution. The approach includes deriving control limits, implementing an optimised repetitive sampling scheme, and evaluating performance using ARL. Simulation studies demonstrate that the proposed chart outperforms existing charts in detecting small to moderate shifts in data distributed according to a Dagum distribution.