The invention is directed method of computer-aided design of edges connecting faces of a modeled object, the method comprising a step of:—determining (S100-S130) a structure of subsets of faces and edges of specified convex or concave type, by iteratively disconnecting (¦S120¦) faces connected by edges of one type from a parent subset, whereby said parent subset is decomposed into child subsets comprising either:—a non-connected face; or—faces connected by edges of the other type, in which case edges of said one type are maintained in said child subset, wherein said one type of edges is further alternated at each iteration of disconnecting; and the method further comprising a step of:—processing (S140) the structure from a given parent subset for rounding or filleting the one or more edges connecting child subsets thereof, according to the type of edge as specified in said given parent subset. More generally, the present invention may further be directed to the design of implementation of two distinct technologies for processing features connecting elements a model, in place of design of edges connecting faces of a modelled object.