Product service system is one new production paradigm for manufacturing enterprises to cope with fierce market competition in service economy environment. Product modularization is an important part of product service system development. In this paper, the design process model of product service system is built on the basis of current product service system modeling methods. Guided by lifecycle-oriented modular design idea, the product function is decomposed and the function units are obtained, which correspond to specific parts in the product. Using fuzzy C-means clustering algorithm based on simulated annealing and genetic algorithm for clustering analysis, the division scheme of product modules is got. Lifecycle-oriented product modular design method pays more attention to environmental attributes of the product, and considers the consciousness of environmental protection and sustainability in product design well. Using CNC machine tools as an example, this paper verifies the reliability, rationality and superiority of presented product module division method oriented on CNC machine tools.

In this paper, considering the porosity defects of Additive Manufacturing (AM), a level set topology optimization method for AM with porosity constraints is proposed. The concept of topological sensitivity is used to formulate a global porosity constraint function in the proposed method, and a level set topology optimization model considering porosity defects is obtained. To improve the robustness of the algorithm, the topology optimization model is solved in two phases. At first, the classical level set method without the porosity constraint is used to initially optimize the structure. During this process, the hole nucleation method combining bi-directional evolutionary structural optimization (BESO) and the topological sensitivity is used. Secondly, the topology optimization considering the effects of porosity is implemented on the preliminary optimization results. After performing the two-step optimization, a robust structure that alleviates the harmful impact of porosity defects is obtained. Finally, the robustness and effectiveness of the proposed method are validated by several two-dimensional numerical examples.

In order to better obtain information about customer requirement and develop products meeting customer requirement, it is necessary to systematically analyze and handle the customer requirement. This article uses the product service system of numerical control machine as research objective and studies the customer requirement modeling and mapping oriented toward configuration design. It introduces the conception of requirement unit, expounds the customer requirement decomposition rules, and establishes customer requirement model; it builds the house of quality using quality function deployment and confirms the weight of technical feature of product and service; it explores the relevance rules between data using rough set theory, establishes rule database, and solves the target value of technical feature of product. Using economical turning center series numerical control machine as an example, it verifies the rationality of proposed customer requirement model.

Product–service system is a new globally optimized production system with high-degree integration of product and service, which is formed under the product lifecycle management thinking of manufacturing enterprises. This paper applies the modular design method in the development of CNC product–service system and studies the module division and configuration modeling method oriented to configuration design process. First, a service module division method based on design structure matrix is proposed, and the relationship of service activities is established through directed graph and the module division of service activities is determined by calculating reachable matrix. Next, the product–service integration strategy is analyzed, the product–service integration model is built, and the organic integration of product and services is achieved. Then, the meaning of configuration model of product–service system is introduced and the configuration model is established. At last, the economical turning center is selected as an example of CNC to implement the module division and configuration modeling of CNC product–service system and to verify the feasibility of proposed methods.