EWMA np Control Chart for the Weibull Distribution

Abstract

In this paper, we will present the design of an attribute exponentially weighted moving average (EWMA) control chart based on the number of failures under a time-truncated life test. It is assumed that the lifetime of the product follows the Weibull distribution. The performance of the proposed chart is discussed in terms of the average run length. The efficiency of the proposed chart is given over the existing attribute control chart. The proposed chart performs better than the existing chart in detecting shifts in the manufacturing process, as compared to the existing control chart. A simulation example is given to illustrate the proposed chart.