The conventional development required much experience, intuition and a lot of trial and error. In contrast, by using the latest design tools can realize efficient development by simulation based discussion. Particularly, the capability of the developer can be improved using "designer CAE" which can use "CAE tool" and "3D CAD" seamlessly. Moreover, the development efficiency of the team can be dramatically improved by combining "WAI-GAYA" which is free technical discussion with discussion which use this "designer CAE". This paper introduces F1 transmission development as an example of this development methodology.