The expertise represents an important capital in a company. The loss of this kind of knowledge has pushed the companies to look for a means to capitalize on it so as to use in the future. In fact, in many companies the design process usually learn from an old similar experience, the designers develop an existent solution, or try to take back old solution in order to adapt it to a new requirement. This tendency to reuse old solutions is strengthened by constraints of time, of efficiency and of search of a maximum of reliability. Therefore, the importance of the capitalization of design project knowledge is more and more increasing. This paper presents techniques to extract and to represent this type of knowledge in a project memory, using Process Life cycle Management (PLM) tools.