In ANSYS WORKBENCH shape optimization module by just providing loads, boundary conditions and entering the percentage of weight reduction the result are computed from mesh, without out specifying any limits for deflection or stress or frequencies the results are directly obtained. These results shows the material to be removed, marginal and material to keep on what basis this result is computed how good this result will be useful to perform topology optimization? To reduce weight in gearbox housing weather this result will be useful