Geometrical Product Specification and Verification (GPS) matrix system is universal acceptable tool for expressing geometrical requirements on product design drawings. It benefits product designers through providing detailed description of functional requirements for geometrical products and referring to corresponding manufacturing processes. Therefore, in order to overcome current implementation problems highlighted in this paper, a GPS knowledge base system and an innovative inference mechanism have been developed, which establishes an integrated GPS knowledge platform to facilitate rapid and flexible manufacturing. This paper starts with a brief review of the project background; it then move on to demonstrate the design and implementation of the proposed virtualGPS system; and the paper concludes with a short working case study and performance evaluation to assess the design functions of the system.