【正文】 D Program of China under the project “Research and demonstrator of rapid manufacturing integrated system based on rapid prototyping” (No. 2001BA205B10 CMTT1001).10 / 10。 and design modification. Therefore, any step of the new product development process has a direct and strong influence on timetomarket in short order. A good product development system must enable designers or design teams to consider all aspects of product design, manufacturing, selling and recycling at the early stage of the design cycle. So that design iteration and changes can be made easily and effectively. The more fluent the feedback is the higher possibility of success the system has. Design for manufacturing (DFM) and concurrent engineering (CE) necessitate that product and process design be developed simultaneously rather than sequentially. The integrated system of rapid product development is posed of four modules: digital prototype, virtual prototype, physical prototype and rapid product development starts from the creation of a 3D CAD model using a CAD software package. At that stage, the product geometry is defined and its aesthetic and dimensional characteristics are verified. The main function of digital prototype is to perform 3D CAD modelling. The CAD model is regarded as a central ponent of the whole system or project information base which means that in all design, analysis and manufacturing activities the same data is utilized. The product and its ponents are directly designed on a 3D CAD system (, Unigraphics, CATIA, IDEAS, etc.) during the creative design. If a physical part is ready, the model can be constructed by the reverse engineering technique. RE is a methodology for constructing CAD models of physical parts by digitizing an existing part, creating a digital model and then using it to manufacture ponents. RE can reduce the development cycle when redesigns bee necessary for improved product quality. Preexisting parts with features for improved performance can be readily incorporated into the desired part design. Therefore, it is very useful in creating the CAD model of an existing part when the engineering design is lost or has gone through many design changes. When a designer creates a new design using mockup, it is also necessary to construct the CAD model of the mockup for further use of the design data in analysis and manufacturing. The three primary steps in RE process are part digitization, features extraction, and CAD modelling. Part digitization is acplished by a variety of contact or noncontact digitizers. There are various mercial systems available for part digitization. These systems range from coordinate measuring machine (CMM), laser scanners to ultrasonic digitizers. They can be classified into two broad categories: contact and noncontact. Laser triangulation scanner (LTS), magnetic resonance images (MRI), and puter tomography (CT) are monly used as noncontact devices. Contact digitizers mainly have CMM and crosssectional imaging measurement (CIM). Feature extraction is normally achieved by segmenting the digitized data and capturing surface features such as edges. Part modelling is fulfiled through fitting a variety of surfaces to the segmented data points.In order to reduce the iterations of designprototypetest cycles, increase the product process and manufacturing reliability, it is necessary to guide in optimizing the product design and manufacturing process through virtual prototype (VP). VP is a process of using 3D CAD model, in lieu of a physical prototype, for testing and evaluation of specific characteristics of a product or a manufacturing process. It is often carried out by CAE and virtual manufacturing system. Computer aided engineering (CAE) analysis is an integral part of timepression technologies. Various software tools available (. ANSYS, MARC, IDEAS, AUTOFORM, DYNAFORM, etc.) can speed up the development of new products by i