Industry and academia are increasingly demonstrating the benefits of Internet based collaborative work for product design and development. For example, collaborating via the Internet for design teams at Boeing, and efforts to understand and support the design process at Stanford University, showed promising results. The U.S. government''s National Advanced Manufacturing Testbed (NAMT) project aims to set standards for future design and manufacturing practices by demonstrating the use of networked machines, software and people [www.mel.nist.gov/namt
]. The NAMT project provided us a testbed to analyse and further explore usefulness of Internet-based collaborative design. In this case study, we have used two different Internet based approaches to support the design process. In our first approach, we have used a client-server based suite of tools to facilitate design activities and capture design rationale. In the second method we used VRML as a communication and visualisation medium for evaluation of detailed designs. We draw observations from both the experiments and analysed them in terms of their benefits for the design process and the end product. In this paper, we report our analysis results, and abstracting from these results, we present a set of requirements to further Internet-based collaborative tools.