1. A method for identifying symmetry relationships, comprising: receiving, in a product data management (PDM) system, a 3D model including a plurality of components; identifying a plurality of target components from the plurality of components; identifying a symmetry plane in the 3D model; determining the location of each of the target components with respect to the symmetry plane; adding the target components to respective groups according to the determined locations; creating an equivalence class for each group of target components; and storing a symmetry relationship between the created equivalence classes.