FOA, which is short for First Order Analysis, developed as an early design analysis method, enables to make Nonlinear Analysis such as large deformation and contact calculated rather faster for constant section elements, and enhances efficiency of mechanical design for spring, cable layout and the like, which are able to be transformed to beam elements. We introduce the mode of operation that we made a surrounding which is enabled instinctive using GUI of FOA is added on 3D CAD system, which is expanded and spread for designers as the tool of mechanical element design, and which is able to reduce the cost and period of design and so on.