We concentrate on the property that the progression of collaborative work involves communication among participants, and we consider a flexible method for managing transactions utilizing structured messages. In the literature, advanced transaction models for collaborative work environment have been proposed. However, since the models treat work process as a target of transaction, it is difficult to adapt to exceptions or dynamic reconfiguration of processes. In this paper, we argue about examples of handling exceptions in an environment involving workflow processes and database transactions, utilizing structured messages. We use the message transaction model for specifying structured messages. The model has ability of specifying workflow processes and various advanced transactions.