This volume documents the concepts, experiences, results, and conclusions of the ESPRIT project NEUTRABAS (Neutral Product Definition Database for Large Multifunctional Systems). It deals with the development of a database for large multifunctional systems, in particular for ships and their multitudinous, complex subsystems. NEUTRABAS was the first European project aiming at an international standard based on ISO standard 10303 (STEP) methodology to define a comprehensive information model for ships and similar products of complex functionality, which will serve for the exchange and long term storage of product information. NEUTRABAS contributed to the first generation of shipbuilding product models and gained first experiences in implementing databases exploiting the new technology of the STEP standard.