Research On Conceptual Design Technology Of Product Service Systems Driven By Customer Requirements

Manufacturing company is turning from a single product design and production to overall solution (including product and service) design and production, which are prompted by the following factors: sustainable manufacturing and consumption, customer for functionality or results provided by product and service together, increasing homogenization of product, and so on. PSS (Product service systems) is a new principle for adapting the strategic transfer of manufacturing company (PSS of manufacturing industry can be called as industrial PSS). PSS design research is the developing forefront of manufacturing field. Conceptual design as the key point, its aim is to establish the overall solution for customer satisfaction.In PSS conceptual design, customer requirements are described from engineering task and construction environments. The design mode has the following characteristics: design objects'heterogeneity (including heterogeneity, combination and match), and design process'complexity (including process interacting, solution diversity and decision making mixing). Traditional design theory and methods can not effectively address the complicated issue. The study proposes a PSS conceptual design framework composed of requirement domain, function domain and concept domain, driven by customer requirements, surrounded with the two scientific problem (i.e. customer requirements'transferring and delivery, and PSS concepts'generating) and taken a typical horizontal directional drilling machine as the design object. The framework can help designers to obtain PSS concepts with higher design quality and design efficiency, which combined with three key technologies: requirement transferring, configuration design, and decision making. The paper is mainly focus on the following aspects:(1) PSS's definition and classification is first analyzed, and existing research systems and techniques are discussed. Two main characteristics and two scientific issues of PSS conceptual design are summarized and main content and innovation of technology research on PSS conceptual design driven by customer requirements are then described. Furthermore, the related methods of PSS conceptual design are reviewed and summarized.(2) Difference with the traditional design, PSS conceptual design framework composed of requirement domain, function domain and concept domain is established based on the expansion of Axiomatic design domain context. Three domains are expressed by using interaction diagram and task model, interaction diagram and functional structure model, and network diagram. PSS concept configuration model is developed and configuration process and configuration model adaptation mechanism is analyzed. Moreover, three key technologies of PSS conceptual design are given. The paper takes maintenance as a typical representative service to unfold the research.(3) Multi-mode mapping method is proposed for translating customer requirements into PSS concept characteristics. Manufacturing enterprises is the transition phase from the traditional design to PSS design and the data accumulated under the new design is small. It is difficult to use intelligent learning method to construct the corresponding mapping space. Therefore, the establishment of parallel-structure house of quality is to achieve the transmission and distribution from customer requirements to PSS concept characteristics. Nonlinear least-squares-based optimization algorithm is proposed to fuse the diverse decision-making information, and negative and positive association rules are used to support objective analysis of house of quality. In order to take full advantage of accumulated product and service data of manufacturing enterprises under the traditional design, an optimization model of PSS concept characteristics is proposed based on GA-BPNN-GA hybrid learning and optimization. Two learning network of product and service are constructed, and PSS concept characteristics are optimized based on task preference, cost constraints (including possible technical requirements), and the match between product characteristics and service characteristics.(4) Interactive configuration design technology is proposed for PSS concept. First, interactive configuration process of PSS concept is analyzed. Based on the analysis of compatibility, synthesis method is developed to fuse service model into service process. Service orientation analysis is performed by using least squares support vector machine, which can be seen as selecting and matching assessment benchmarks between service and product. Second, risk degree is the key information between product and maintenance, and a risk calculation model and incomplete ranking model is proposed based on the method of imprecision. The model can improve the reliability of risk calculation based on quantitative compensation between risk indexes. An incremental and variable-precision rough set is used to mine product or service configuration rules, which can ensure the effectiveness and updating of the model configuration.(5) PSS concept has hybrid characteristics, including the mix of product and service, the mix of qualitative indexes and quantitative indexes, and the mix of design information and decision-making information. First, the extended service blueprint is used to construct PSS performance model, which can effectively assess the overall consistency and matching. Second, the mix of design information and decision-making information can ensure the consistency and reliability of the results. Finally, a hybrid decision-making model is proposed to achieve PSS evaluation under qualitative and quantitative indexes. The improved TOPSIS method based on Kano is developed to accurately sort and prefer PSS concept.The study establishes a new design system and methodology for PSS concept design, lays a theoretical foundation for the further research of this field, and also provides technical support for customer requirements'transferring and distribution, configuration design and concept'decision making of PSS conceptual design. The proposed method is applied in a real world PSS case of horizontal directional drilling machine and good results is achieved.Acknowledgements: This dissertation is supported by National Natural Science Foundation of China (No. 51075261), Shanghai Grand Science and Technology Research (No. 04dz11005).