Bayesian Dynamic Quality Control Method for Multi-Variety and Small Batch Production

A dynamic quality control method is proposed to deal with the problem of quality control for multi-variety and small batch production. The group technology is adopted to select data from production batches in the past, and then the data are transformed to serve as the prior information. Following the conjugate Bayesian theory combining with the exponential weighting idea, the X-MR control chart is modeled and the process capability index is calculated. This strategy can real-time evaluate the control limit according to the characteristic data of quality to dynamically control the production process. With the increasing current batch data, the obtained control limit gradually approaches the actual value, and the control effect is gradually improved. Simulation results show the higher accuracy in estimating the control limit and the stronger detection power than those of the existing methods. © 2019, Editorial Office of Journal of Xi'an Jiaotong University. All right reserved.