The characteristics of simulation results in metal forming were analyzed. In light of the deficiency of the discretization method, as a pre-process for rough set method, a fuzzy-rough algorithm was proposed for data mining on numerical simulation results. Taking the square box's drawing process in NUMISHEET'93 as an example, this paper did numerical simulation. Through knowledge discovery from the simulation results using fuzzy-rough method, many instructive what if rules were induced. Every rule has a reli...