Number Of Studies On Dynamic Ewma Control Chart

The dynamic quality control chart is more efficient than the static quality control chart. In this paper, some research about dynamic exponentially weighted moving average control chart is given. The main tasks are below:1 The dynamic EWMA mean control chart is extended to EWMA variance control chart. The EWMA variance control chart with variable sampling intervals under normality is proposed.2, The Shewhart mean control chart under non-normality is extended to EWMA mean control chart. The EWMA mean control chart with variable sapling intervals under non-normality is proposed.3, The one-dimensional EWMA mean control chart is extended to two-dimensional EWMA mean control chart. The two-dimensional EWMA mean control chart with variable sampling interval control chart under normality is proposed.The Markov Chain method is used to calculate the average time to signal for the three kinds of proposed control charts. The proposed charts are also compared with the corresponding fixed sampling interval control charts. The datum show that the proposed control charts can sharply shorten the out of control time and are more efficient in detecting the rejects.