Study On Flexible Production Planning And Control Technologies Of Mechanical Products In An Assembly-to-Order Environment

Mass customization (MC) aims to provide individualized products to every customers with the cost and speed of mass production, and it wins a great popularity in 21st century. In the context of MC, related technologies covering the modeling of product family extended information, flexible organization of supply chain, supplier selection and order splitting, and theories and methodologies of production planning and control are investigated in depth.Agility is the main external characteristic of mass customization, and flexibility is the internal power to realize agility. The main methods to enhance agility are prescribed from the facets of products, manufacturing, production and operation, information system, organization, and human resources. The concept of supply chain under MC (MCSC) is defined based on the comparison of agile supply chain and lean supply chain. Further, functional and architectural frames of the resource planning system oriented to assembly to order environments in the MCSC are built by taking the characteristics of production control in MC into account.With a focus on the characteristics of product information in MC, the author defines the extended product family information model, which consists of product family structure model based on Generic Bill of Materials (GBOM) and product information model. The extended model enables the structural model to include the product family information related to the design, procurement, planning, manufacturing, stocking and marketing. It is mapped to six different domains. Product family extended information models are built using the object-oriented technology and are mapped from logical models into physical models. Three types of classes, i.e. entity object class, object management class and object collection class are abstracted. To enhance the efficiency of product configuration, the optimized configuration model and relative algorithm are made based on Constraint satisfaction problem (CSP). For product family extended information models, XML Schema-based product information integration schema and product family configuration information integration schema are established. These schemas serve as the standards for integrating the product family information physically distributed among various manufacturers, distributors and suppliers.Based on the characteristics of the purchasing management under MC, a multi-sourcing policy is proposed to reduce the risks that may appear in supply chains. For either implementation method of multiple sourcing, specific models of suppliers' selection and procurement order splitting on the multi-sourcing basis are built to obtain the lowest average purchasing cost, considering constraints of demand, supplier's capacity and quality. A synthetical algorithm based on branch and bound algorithm is presented for simultaneous supply model. A comparative analysis between single- and multi-sourcing settings is conducted. In particular, the suppliers under MC are treated as key ones and normal ones. With normal ones, a double-layer process model for supply chains in a multi-supplier environment is proposed to improve the flexibility of supply chain and to lower the procurement cost.The characteristics of production planning under MC are analyzed and a flexible and layered production planning and control system is built. The production plan in a supply chain is discussed from the perspective of strategic-, tactic- and operational layers. A planning control strategy enables flexibility and stability is adopted for the production planning of common parts, while an order-rolling control mechanism is used for the order scheduling process. With the object-oriented method, order information models and order lifecycle models are built, and the order object status diagram is proposed consequently. In the context of multi-order multi-product and multi-resource of manufacturing, the order scheduling problem are discussed by building a multi-objective integer programming model and devising a multi-objective genetic algorithm based on pareto selection and individual transference. Finally, a case study validates its high efficiency.The supply chain resource planning system, which consists of three types of components including interface components, business logic components, and data maintenance components, is designed and coded using the Component-based Development (CBD) method, the method enables rapid reconstruction depending on the changes of business requirements and improves the flexibility of information system.Finally, the supply chain resource planning system is put in practice in Shandong Wuzheng Group. The practical and successful operations of customer order management oriented to configuration, production planning, purchase planning under multi-supplier environments, optimal scheduling, final products and common parts' inventory management are introduced. The results validate the theories forwarded in the thesis.