It is proposed a method, performed by a computer system, for designing a multi-physics system. The method comprises the steps of displaying a block diagram representation of the multi-physics system, including blocks that each correspond to a respective sub-system of the multi-physics system, and, between the blocks, links that correspond to multi-physics connections between the respective sub-systems; and upon a zoom command, sent by a user, displaying a preview of a block diagram representation of at least one respective sub-system, the displaying of the preview being controlled by the detection, by the computer system, of the zoom command.Such a method improves the design of a 3D modeled object.