A study has been completed to investigate existing STEP protocols for the purpose of reliable routine CAD data exchange between companies involved in European space projects. The evaluation concentrated on STEP Application Protocols AP-203 and AP-214 because of their broad support and maturity. The study concluded that STEP AP 203 and 214 are sufficient mature to be introduced as CAD data exchange standard in European space industries. In the meantime a working group (WG) promoted by ESA (European Space Agency) has recently been created to establish relevant standards within the European Cooperation for Space Standardization (ECSS). This study has been presented to the WG and is considered as baseline to establish guidelines for product data exchange to be issued.