To develop more competitive products, more and more attentions are paid to the study of user participation in the process of product design. But the study to grasp user's needs and wants on the form of the products besides its functional aspects and apply it to designing new products is insufficient. This thesis is purposed for the designers to develop a systematic process by which they can come to the fore user's needs and own ideas and extend them to be appropriate solutions on the phase of form development of designing new products.
At first, this thesis introduces the basic objectives and principles of the development of user participatory process by reviewing and summarizing the historical background and its main issues. Then, the present situation and the prospect of user participation in each phase of product design process is examined and as a result, the need of more substantial user participatory process for the phase of form development is emphasized. Next, the phase of form development is analysed by subdiving into four stages - verbal image generation stage, visual image transformation stage, subsolution generation stage, user image structure analysis stage - and the concrete model of user participatory process and its application program is developed by analysing and applying decision making models and problem solving techniques which are appropriate to the characteristic of each stage. Then, the discussion of the effect which can be drived from the utilization of computer and information technologies is followed and based on the precedent result, the prototype of design information system for user participatory design process on the phase of form development is developed and its operation process are also presented in detail. Finally, findings of this study are summarized and further study are proposed.