A method for editing a 3D computer-aided design, CAD, model in a display window of a graphical user interface, comprising: receiving, in a product data management,PDM, system, the 3D CAD model including a plurality of components; receiving a selection of one of the plurality of components of the model; receiving a selection of at least one equivalence relation to be discovered in the 3D CAD model, wherein the at least one equivalence relation is one or more of Identical,I, Same Center,SC, Same Axis,SA, Same Plane,SP, Same Shape,SS, and Same Direction,SD, wherein the PDM system uses a hierarchical structure among these equivalence relations from a first relation being the strongest relation to a last relation being the weakest relation, wherein Identical is the strongest, then Same-Center, Same-axis, Same-plane and Same-Shape, and finally, Same-Direction being the weakest; identifying at least one target component of the plurality of components of the 3D CAD model that will be compared against the selected component; completing the selected component with respect to each target component according to each selected equivalence relation by comparing the selected component to each target component with respect to each selected equivalence relation, wherein when one equivalence relation is met between any two components of the 3D CAD model, then all weaker equivalence relations are met between those two components, wherein the process is repeated for each target component, and each equivalence relation, in the hierarchical order; and building and storing an equivalence relationship graph according to the completed selected component; editing the 3D CAD model while maintaining the selected equivalence relations. receiving, in a product data management,PDM, system, the 3D CAD model including a plurality of components; receiving a selection of one of the plurality of components of the model; receiving a selection of at least one equivalence relation to be discovered in the 3D CAD model, wherein the at least one equivalence relation is one or more of Identical,I, Same Center,SC, Same Axis,SA, Same Plane,SP, Same Shape,SS, and Same Direction,SD, wherein the PDM system uses a hierarchical structure among these equivalence relations from a first relation being the strongest relation to a last relation being the weakest relation, wherein Identical is the strongest, then Same-Center, Same-axis, Same-plane and Same-Shape, and finally, Same-Direction being the weakest; identifying at least one target component of the plurality of components of the 3D CAD model that will be compared against the selected component; completing the selected component with respect to each target component according to each selected equivalence relation by comparing the selected component to each target component with respect to each selected equivalence relation, wherein when one equivalence relation is met between any two components of the 3D CAD model, then all weaker equivalence relations are met between those two components, wherein the process is repeated for each target component, and each equivalence relation, in the hierarchical order; and building and storing an equivalence relationship graph according to the completed selected component; editing the 3D CAD model while maintaining the selected equivalence relations. <EOS>