In this report we discuss the architecture of the Collaborative Process Managers (CPMs) used to support inter-enterprise collaboration. A CPM must provide three logical functions, the conversation management for handling interenterprise document flows; the process management for controlling local workflows of document manipulation and other related tasks; and the action management for invoking local services that actually implement these tasks. Conversation models and workflow models have some similarity as well as considerable differences. The provisioning, interaction and integration of these three functions are very practical challenges faced by many organizations. Particularly, extending existing workflow engines for supporting inter-enterprise business collaboration, has become the common interest of the e-business industry. We shall first compare five different CPM architectures based on our own prototypes, and then propose the architecture characterized by interfacing a conversation manager and a process manager through asynchronous task activation, and by using the conversation manager as the conversation model driven task activator for local process management. Our experience reveals the advantages of this architecture over the others, as it allows the maximal usability of existing workflow system components, supports both conversation flow and local work flow, and provides a dynamic and simple interface between conversation management and process management. Further, by providing conversation managers under different conversation models, a CPM can support multiple interenterprise interaction standards.