Development of six sigma-based control chart for standard deviation under robust measure

The number of defects is frequently used to evaluate or measure quality. Quality may reduce errors, rework, and defects while increasing output from the same input. Thus, productivity increases, according to Duncan (1958). Consequently, a business that produces high-quality products will frequently witness an improvement in manufacturing productivity. When the underlying normalcy assumption is not fulfilled, a control chart based on six sigma and employing the interquartile range (IQR) for standard deviation is offered in this research paper as an alternative to the current control chart. This control chart performs better than the Shewhart (1931) control chart.