1. A method for guaranteeing generation of 2D sketches based upon a 3D sheet metal part shape, comprising: performing a sheet metal feature operation to create the 3D sheet metal shape, which has multiple flanges to be made by bending operations; and generating a separate editable 2D sketch for each flange to facilitate editing the 3D sheet metal shape, wherein separate editable 2D sketches for each flange are generated for every type of feature operation used to create the 3D sheet metal shape, and the 3D metal sheet shape is edited base upon edits made on the separate editable 2D sketches for each flange.