Nowadays, systems designed by industrial groups become more and more large and complex. These companies have to employ numerous architects and engineers in order to understand the needs, analyse the complexity and design the system. Architects and engineers have to share the system concepts during the stages of the building process. Requirements are like a contract which is an input they have to take in account. These requirements need to respond to high level criterias of quality (they have to be concise, unambiguous, complete etc.) . In this paper, we propose an approach to write better requirements and to share the systems concepts in an elaborate manner, among the design teams.