  The control of the costs, as soon as possible of the product life cycle,
became a major asset in the competitiveness of the companies confronted with
the universalization of competition. After having proposed the problems related
this control difficulties, we will present an approach defining a concept of
cost entity related to the activities of the product to be designed and
realized. We will then try to apply this approach to the fields of the sand
casting. This work will highlight the hierarchisation difficulties with the
entities composing the models created as well as the limits of a generic
approach.
