Abstract : Tools resulting from the Computer Supported Cooperative Work (CSCW) field, which are often centralized, are increasingly designed to adhere to the system organization using a distributed architecture. However, generally these systems have difficulty in managing data coherency at the global level. In answer to this problem, we turned towards a particular organizational model: holonic systems. This concept has guided us in the specification of a Holonic Multi-Agent System (HOLOMAS), which offers a good compromise between the distribution of knowledge and control centralization. This HOLOMAS has been specified in a particular goal: assistance to actors of cooperative processes in a department of a large company.