Resumen de Evaluating and Improving the Unit and Group-Runs Chart
A unit and group-runs (UGR) chart designed to detect the increase in fraction nonconforming under 100 percent inspection outperforms other attribute control charts in terms of the zero-state average time to signal, but often produces a false alarm if the process starts from an in-control status. Also, the out-of-control performance of the UGR chart under the steady-state mode is unsatisfactory. A method is proposed to improve the UGR chart by minimizing the zero-state average time to signal. At the same time, the out-of-control performance under the steady-state mode can be improved.
