| New product development (NPD) is a process from none to some and from ambigious to clear, which contains large amount of coupled design activies, making the whole process extremely hard to control. Based on this charactersteristic, this paper conducts research on design process construction and design process planning, aiming to achieve the creativity and rapidily of the NPD.Chapter1, the content of the product development process and the research status of the scheme solving in conceptual design is described; moreover, the research on modeling, planning and management of NPD is summarized. Based on the review, the current research problems are analized and the primary research contents as well as the organization of this thesis are given.Chapter2, aiming at the problem that the multi-layer mapping process model of conceptual design lacks efficient methods on concept generation, a new process model, that is the scheme solving tree (SST) and design route tree (DRT) based process model, is proposed. SST, serves as the original model, describes the multi-layer mapping process from abstract requirement to specific structures, while DRT, serves as a derived process model, directly shows all the routs hinden in SST that describe the generation process of conceptual design scheme. According to the hierarchical division of function-prinple-chunk, the scheme solving process is described by symbolic correlation matrix; besides, the design information, including function, principle, chunk, is defined and their knowledge expressing model is given out. This entire research probides basis for achieving the concept generation and decision based on the proposed model.Chapter3, based on the conceptual design process model of SST and DRT, a path decision based computational algorithem for concept generation is proposed. According to the transformation relationship of SST and DRT, a matrix-based algorithm is put forward to realize the construction of DRT, through which the combination explosion problem in transformation is successfully avoided; further more, a similarity-based algorithm for calculating weight in DRT is proposed, which using the knowledge expression model of design information as the evaluation basis, and employing similarity measure of similar units and functional order relation to determine the weight and construct the weighted DRT. Thus, the generation and decision of the conceptual design schemes generation are transformed into the construction of DRT and the best route decision in DRT. The established computational algorithm for conceptual design could prevent the creativity of the design process from degradation.Chapter4, based the concern that the the design activities of the design process have modular characteristic in nature as well as the reality of the enterprises’desire for process reusing, an immune algorithm based modularization planning for design process is proposed. The Numerical Design Structure Matrix Family (DSMF) based methodology is employed for process modeling, in which the transformation of multi-DSM model to single-DSM model and the bool DSM to numerial DSM is realized, so that the in-depth interations in the process are described; an immune modular recoganization algorithm is proposed to achiece the process partition, in which both the modularization perspective and the process planning perspective is considered and transferred into reasonable objective function; for the partition results, two reengineering strategies, which are task decoupling and task combination, are provide to further optimize the process structure according to practical situation.Chapter5, a NPD orientation computer aided process management system is preliminarily developed, in which two key technologies are realized by modular programs. Associating with the case of "Developing Equipment for Automatically Bonding Silicon Rubber Belt", the flow of the system implementation is introduced.Chapter6, all achievements of the thesis are summarized so as to put forward the further research direction. |
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