A wire harness constituted by bundling a plurality of pieces of line streak members by a predetermined exterior member is regarded to be an elastic body having a circular shape and coupled with a plurality of beam elements maintaining a linearity to form a model and a shape of the wire harness is predicted by utilizing a finite element method. When an end portion of the wire harness is displaced by an input apparatus, a shape 1c physically in equilibrium is automatically calculated by the finite element method and is drawn again. That is, the shape physically in equilibrium is automatically calculated and drawn by following a shape design by well-known operation by CAD at a background thereof.
