Flexible CAD format

A method of translating a Computer Aided Design CAD model of a product constructed for Computer Aided Engineering CAE analysis into a flexible form, the method comprising: converting the original CAD model into a different format to provide a new-format CAD model; providing visualization data including: an assembly tree extracted from the original CAD model, the assembly tree including each component of the assembly forming the product; and visualization information from the original CAD model for each assembly face in the assembly tree; and providing geometry information including matching information unambiguously identifying each assembly face; wherein the geometry information allows the assembly faces to be matched with the CAD faces in the new-format CAD model.