Moreover, the costs distribution (respectively direct and non direct) is changing: more time and services are dedicated to the studies for smaller products batches and shorter product life. The former fees sharing-out methods, the analytic or analogical cost-accounting methods, no longer give efficient results. Then, thanks to studies from CAM-I (Computer Aided Manufacturing-International) and authors like Johnson and Kaplan, the increasing gap between “traditional methods” of cost estimation and the new management requirements were highlighted.