A system for managing design parameters in a plurality of different CAD systems flexible for the plurality of different CAD systems having essentially different design purposes. In a method for managing design parameters being used in a plurality of different CAD systems, respectively, in order to prevent prolongation of the completion time of the entire design of a product, arbitrary design parameters in the design parameters being used in the plurality of different CAD systems, respectively, are brought into a virtually shared state among the plurality of different CAD systems. Design parameters in the virtually shared state and design parameters not in the virtually shared state are managed independently.