Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for receiving a definition of a version of a part family comprising a plurality of parts, each part having a same shape and a different respective size, wherein the definition includes a set of parameter values for each part of the part family; storing the definition along with other versions of the part family in either a parametric or parametric-independent format; receiving a request for the part family for a particular computer-aided design system; converting a latest version to a different format that is compatible with the particular computer-aided design system; and providing the converted part family in response to the request.