1. A casting design system ( 101 ), comprising: a database ( 115 ) which contains casting design data and rules; a user interface ( 109 ), in communication with said database ( 115 ), which accepts as input a product design ( 103 ) that is to be cast by a casting process; and an inference engine ( 111 ) which is adapted to generate casting designs ( 114 ) from the input product design ( 103 ) by searching the database ( 115 ) and retrieving data therefrom.