A specification plan of an order-made product suitable for a building structure plan is generated promptly.A WWW server 11 and a database server 12 are provided to the equipment designer's side. The database server 12 has a drawing database 9 that registers a CAD symbol for each product. A CAD symbol for each product includes: effective space information, which expresses a space to be secured for installation of the product; product name information expressing a name of the product; structure information expressing structural features (size, shape, etc.); product specification information; option data; etc. On the other hand, WWW server 11 has a symbol generation data interface 3, through which requirements specification data for an order-made product can be received from a WWW client terminal 2, and a CAD symbol of the order-made product can be taken out from the side of the WWW client terminal.