Research On Methodology Of Product Family Design For Rapid Response To Customers' Requirements

Rapid changing and constantly segmented market, as well as diversified and individualized customers' requirements, forms a new dynamic competitive environment and makes mass customization the mainstream production pattern in the 21^st century. And design based on product family is the key technology to implement mass customization. The objective of product family design is to provide customers individualized products as soon as possible with the lowest cost. Focusing on this scheme, customers' requirements analysis, planning and comprehensive evaluation of product family are put forward. The primary contributions are as follows.First, research on methodology of product family planning. Analysis on difference between product family design and traditional single product design is carried out and a systematic structure model of product family design based on multi-agent is established. Through cooperation between the sub-agents, the optimal design taking customization as kernel and product diversity and commonality as optimization objective is implemented. And then the operation principle, key technology and cooperative solution are discussed. Agents cooperate with each other's through the relationship and nesting in knowledge to achieve the global optimization, and the system can be upgraded through renew and expand agent. The objective of global optimization is achieved through connecting and nesting between every sub-agent and the capability of the system is updated by renewing and extending the sub-agents.Secondly, research on data management of product family design. In order to achieve intelligent intercommunion between the agents, a product family data model based on ontology is put forward and network bill of material is set up to express the relationship between customers and functions of product family as well as the relationship between parts of product family. The establishment of product family data management system manages to describe product family information during the stages in the entire life cycle of product family with a uniform expression, which implements data interactive exchange and maintenance of database.Thirdly, research on the expansion and clustering analysis of customers' requirements based on ontology description. The method to mine and predict customers' requirements is proposed. Holographic semantics based on ontology is adopted to describe customers' requirements and the relationships between them. According to available customers' requirements and product information, quantitative and qualitative expansion of requirements is carried out in the aspects of requirement features, feature attributes and relationship between requirements. Qualitative expansion provides requirements for horizontal series while quantitative expansion does this for vertical series. Finally, in light of difference between customers' requirements, customers' requirements are clustered to reasonably plan diversified types and series for product family design.Fourthly, research on product family synthesize evaluation. Comprehensive optimized evaluation model based on evaluation of diversity of customers' requirements and commonality of product family is presented. Difference in the product family is analyzed and then reasonable but diversified product types are determined. Furthermore, the method to estimate cost of similar products based on case-based-reasoning is put forward and evaluation on commonality of product family is conducted. Besides fulfilling the individualized and diversified requirements, the final objective to lower cost is achieved by enhancing the commonality index of modules, components and parts of product family.Finally, research on clustering model of product family modules based on grey relational grade and similarities. By taking customers' requirements as the start of product family modules clustering, and taking the optimal result of comprehensive evaluation on product family as objective, analysis on relational grade and similar grade of function and structure of the products in the product family. Through clustering, combination and reorganization of similar modules, modularized planning of product family is carried out, which improves both the commonality and the modularity.The main contribution of this dissertation is to enrich and ameliorate the theory and methodology of product family design. Its value in engineering application lies in the guidance to enterprise's rapid response to diversified and individualized customers' requirements, lowering product cost and effectively implementing mass customization.