On the Development of EWMA Control Chart for Inverse Maxwell Distribution

Variations are usually present in every manufacturing process. Control charts are implemented to detect the assignable cause variations in the process. In this article, we design an EWMA chart under the assumption of inverse Maxwell distribution (IMEWMA chart). We have evaluated the performance of the proposed chart in terms of various run length (RL) properties including average RL (ARL), standard deviation of RL (SDRL) and median RL (MRL). To examine the overall functioning ability, we have estimated extra quadratic loss (EQL), relative average run length (RARL) and performance comparison index (PCI). We have also carried out comparative analysis of the proposed chart with the exiting Shewhart type chart for Maxwell distribution, V chart. We observe that the proposed IMEWMA chart perform better than the V chart to detect small and moderate shifts. The IMEWMA and the existing charts are applied to monitor the lifetime of car brake pads and survival time for breast cancer patients. This example also depicts the superiority of the proposed chart to its existing counterparts.