Cooperative work techniques are becoming very important in organisations as well as in the information systems community. The Computer Supported Cooperative Work (CSCW) discipline makes the assumption that collaborative work can be supported by software tools. This requires among others to develop models able to represent cooperative work processes. This paper presents a meta-modeling framework to deal with a range variety of cooperative work models. A cooperative process meta-model from which models can be instantiated is introduced and exemplified. The meta-model is taylored to support the modeling of both well-structured and ill-defined work processes and their interactions.