This paper describes an approach to support cooperation in workflow based on the combination of a cooperative transaction protocol (COO) and a traditional workflow model. This combination allows activities to exchange data during their execution. It also allows some activities to start in advance on the predefined control flow (anticipate) and to exchange results with its preceding activities. All these communications of draft results are done under the control of the extended cooperation protocol and under the responsibility of the users. This allows for more flexibility regarding the actual execution of the process model while keeping some control on the way the exchanges are done.