This paper describes the activities of Object-Oriented (OO) analysis that were implemented in order to obtain a high part representation level and to give sets of structured and hierarchical data to the Computer Aided Process Planning (CAPP) system. The OO modeling activities were carried out by using the Object-Oriented System Analysis (OOSA) method which allows careful specification of all the information contained inside the system. All the models used by this method have been described in detail to show how the OO database is defined and how it can be used by a generative CAPP system. The feature model proposed is defined by taking all the part information that can be recognized and extracted from the Computer Aided Design (CAD) model into account. The result is the design of an OO database which allows the CAPP system to use manufacturing features to define machining operation sequences of 3D workpieces. The approach proposed is generic enough to integrate any geometrical forms which can be recognized and identified from the CAD system. Hole geometry is taken as an example to show the link between the step of OO analysis and the step of knowledge representation in the Expert System which has been used to generate machining cycles. The OO database presented makes up a real solution of CAD/CAPP/CAM integration by using feature modeling.