In this paper, we propose an architecture for adaptive real-time workflow-based collaborative system. Such a system is needed to support real-time communication and sharing of information among predefined or ad hoc team of users collaborating with each other for the execution of their respective tasks in the workflow. A key requirement for real-time workflow system is to provide the right data to the right person at the right time. In addition, the workflow needs to be reconfigured if a subtask of a workflow cannot be executed within the due time. We use the generalized temporal role-based access control (GTRBAC) model to capture the real-time dependencies of such workflow applications. In addition, support for triggers in GTRBAC allows dynamic adaptation of workflow based on the occurrence of certain events. Such adaptations may include rescheduling of workflow tasks, reassignment of users to scheduled tasks based on their availability and skill level, and abortion of incomplete tasks.