This research aims to permit a simultaneous visualization of primary and secondary functions, sub-functions and subsystems in order to establish, according to its position in the plane, the influence on the overall function and how it can be inserted into the product design. The methodology described consists of an in depth-study of the functional deployment starting from a basic need. Since it is a conceptual study with a philosophical approach, three hypotheses underlie this methodology: the union of two techniques of functional deployment is not possible since there is no correlation; the union of two functional deployment techniques provides similar result if applied separately or the union of two functional deployment techniques provides better results since it allows a comprehensive view of the project. Until this point, this research suggests the union of the two functional deployment techniques provides better results since it allows a comprehensive view of the project.