On Designing a New VEWMA Control Chart for Efficient Process Monitoring

This study proposes a new memory type control chart named V-exponentially weighted moving average (VEWMA) control chart to monitor Maxwell distributed quality characteristics. We evaluated the performance of the chart using different run-length properties, including average run length (ARL), the median of run-length (MDRL), the standard deviation of run-length (SDRL), and some useful percentiles of the run-length. A comparative analysis is conducted with the existing V -cumulative sum (VCUSUM) and V charts for Maxwell distribution. We observed that the overall performance of the proposed chart is superior as compared to other control charts for the Maxwell distribution in terms of ARL and MDRL. Moreover, the VEWMA chart outperforms the V chart for small shifts, while for larger shifts the V chart dominates. We have provided a simulation study and a real-life example based on the Maxwell distribution to monitor the lifetime of a vertical boring machine of an ongoing process.