A New Control Chart Based on a Bivariate Beta Distribution

In many practical situations, the quality of a product can be measured based on some quality characteristics in terms of the sum of the percentage of these characteristics utilities. In these cases, control charts based on multivariate beta distribution can be used to monitor the process. This study aims to introduce a new control chart for monitoring the quality of products when two quality characteristics follow a bivariate Beta distribution. The efficacy of the proposed control chart is evaluated using the average run length criterion using a simulation study. In the case that the parameters of this distribution are unknown, the maximum likelihood method is applied. Then, using a simulation study, the performance of the proposed charts, in two cases known and unknown parameters are compared.