The data exchange between Computer-Aided Design (CAD) systems is a crucial issue in concurrent engineering and collaborative design. The paper presents research works and techniques dealing with the interoperability of a Cooperative Design Modeller (CoDeMo), aiming at the integration of product lifecycle knowledge, and a commercial CAD system (CATIA V5). Two kinds of approaches are implemented in the considered case of CAD interoperability for exchanging geometric data, respectively: one is based on a traditional static interface, in which STEP AP203 standard is used; the other is based on a dynamic interface, in which Application Programming Interfaces (API) of the targeted CAD system is adopted. Both approaches should enhance the communication, exchange and sharing of product data between CAD systems for improving concurrent engineering. A comparison between these two approaches is made to show their particular advantages and disadvantages. The development of a translator between the both CAD systems based on each approach has been carried out and evaluated on an assembly case.