Research On Production System Performance:Modeling,Evaluation And Improvement

Production systems play an important role in the modern manufacturing industry.The analysis,evaluation and continuous improvement of production systems is crucial to the enhancement of system performance and financial benefits.However,there are various features and requirements in practical production systems and many of them have not been analyzed thoroughly.On the other hand,the rationality of performance measurement systems in production processes,as well as the intrinsic relationship between KPIs(Key Performance Indicators),needs more systemic investigation.Therefore,in this dissertation we build theoretical models to study the system performance,control,optimization and measurement.Firstly we focus on the performance evaluation and optimal control of production systems by investigating three typical system configurations,including a multi-product system with arbitrary processing time,a multi-product system with geometric machine reliability,and a system with residence time restraints.To deal with each of them we build a Markov chain model to give the theoretical results of system performance and then propose estimation methods with high accuracy.Based on the models we investigate the theoretical properties and propose an optimal control policy for the last two systems.Results show that the models can evaluate the system performance with high accuracy and possess high practical value.Another topic of this dissertation is on the KPI structure of production systems and its classification and relationship.Different from traditional statistical approaches,we study the intrinsic relationship among the KPIs based on their definitions.We use a practical case to validate that the hierarchical KPI structure proposed in this dissertation can effectively direct the continuous improvement of production systems.The results of this dissertation not only contribute to the theoretical research of production systems,but also provide managerial insights to the analysis,control and measurement of practical production systems.