By integration of traditional database, distributed AI (DAI), and computer supported cooperative work (CSCW) research areas, new cooperative information systems which offer efficient storing, retrieving and recovering of data, as well as communication, synchronization and coordination could be developed. Such systems are called groupbase systems. The CODA model (COoperation model for Design Applications), a groupbase system tailored to design applications, is presented. Beside the integration of communication features, it uses a flexible locking technique which overcomes many drawbacks of traditional concepts. It offers coordination techniques and a new approach to consistency maintenance which is more appropriate to design than traditional serializability-based concepts.< >