Abstract: The research on product configuration design process and management is important for supporting and applying product configuration in mass customization. Product configuration can be thought as a process of instantiating configuration model in meeting consumer needs. In this process, the components that are not covered in components bases need to be designed. The product configuration design process has some distinguished characteristics from the general product design process. In this paper, after the main contents and work flows of product configuration design are introduced, a model on product configuration design process is presented. With regard to the model, three decomposition structures, three decomposition layers and two templates are introduced, and the instance unit data are well integrated into design tasks. The model proposed and the decomposition methods are verified by an example of elevator design.