It is well known and widely accepted that the conceptual design is the most influential step in the design process of a product or a system and that about 75% of the life cycle cost is committed as the results of this stage. The purpose of this paper is to present and demonstrate the step of ICDM(Integrated, Customer Driven, Conceptual Design Method) for the development of a ground launcher system, TEL(Transporter, Erector and Launcher). The results of the study show the effectiveness of the method during the conceptual design phase of new complex systems or high-tech products.