An application server reads components data from a component information system (CIS) of a database server connected to the application server. The components data are converted to HDL data. If the converted HDL data includes illegal characters, a user is prompted to modify the illegal characters. If the converted HDL data does not include illegal characters, the application server amends formats of the converted HDL data according to requirements of each client connected to the application server. Each client includes a drawing unit. The application server controls the drawing unit to draw circuit diagram using the HDL data with the amended formats.