A Nonparametric Group Runs Control Chart for Location Using Sign Statistic

Abstract

In this paper, we propose a nonparametric group runs control chart using sign statistic for monitoring the shifts in the process location. Performance of the proposed control chart is measured using average run length, standard deviation of run length and percentiles. The study reveals that the proposed nonparametric group runs control chart performs better than the existing nonparametric control charts based on the sign statistic viz sign chart, the synthetic chart, the 2-of-2 chart, exponentially weighted moving average chart and cumulative sum chart. Implementation procedure of the proposed chart is explained using a numerical example.