This paper proposes a new combined scheme (termed as Mnp-EWMA scheme) for monitoring multi-attribute characteristics. The proposed Mnp-EWMA scheme combines both the multi-attribute np (Mnp) and multi-attribute Exponentially Weighted Moving Average (MEWMA) charts for effective monitoring fraction nonconforming. In this study, the Average Number of Defectives (AND) is used as an objective function in an optimization model to identify the best design variables of the proposed Mnp-EWMA scheme. The performance of the proposed Mnp-EWMA scheme is compared with that of the Mnp and MEWMA charts under five scenarios with the different inputs of design specifications. The results show that the Mnp-EWMA chart outperforms the Mnp and MEWMA charts under different settings.
Published in6th North American International Conference on Industrial Engineering and Operations Management, Monterrey, Mexico