Research On Optimal Design Method Of EWMA Control Chart Based On Minimum Production Cost

How to improve product quality,reduce production waste,reduce manufacturing cost is a key issue in the Development of China 's Manufacturing Industry.Scientific quality management can not be separated from the effective statistical analysis technology.In this paper,the EWMA control chart which can can detect the small mean shifts is designed from the economic view of production cost.The EWMA control chart cost optimization model is set up to minimize the cost production.The optimization algorithm is realized to obtain the optimal EWMA control chart parameters and the engineering application is verified.First,Considering there is quality loss in the actual production process,an optimization design model of EWMA control chart based on quality loss is established.The quality loss cost under the in-control state and the out-of-control state is estimated by the Taguchi mass loss function.Four scenarios are defined,the model of EWMA control chart is set up to minimize the expected production cost as the objective function,The genetic algorithm is used to solve and optimize the model parameters,and the economic performance of the model is verified by case analysis.Then,the cost of maintenance was considered based on quality loss cost in the last chapter,an optimization design model of EWMA control chart based on maintenance strategy is established.Under the assumption that the out-of-control process and equipment failure is a correlation with the different random process.Five scenarios are defined.By the cost structure analysis and the reliability theory,the occurrence probability,cycle time and cycle cost are then calculated,the model of EWMA control chart is set up to minimize the expected production cost as the objective function,The comparison model is designed and the genetic algorithm is used to solve the problem.The results show thatthe method has obvious advantages which was compared with the "repair-plan maintenance" model.Finally,the inventory cost was considered based on the quality loss and maintenance strategy in the last two chapters,an optimization design model of EWMA control chart based on inventory control is established.Under the assumption that the process mean shift is a random variable,four scenarios are defined,the occurrence probability,the cycle time and the cycle cost are analyzed,then desige the economic production batch.The model of EWMA control chart is set up to minimize the expected production cost as the objective function.The corresponding algorithm is used to solve the engineering case and the parameter sensitivity analysis is carried out.