Knowledge-intensive processes are characterized by vague specifications and a dynamic course of action. They require a flexible, knowledge-based enactment environment supporting the dynamic allocation of resources, changes in assignments, organizational structure, policies, and requirement and priorities, but also conflicts between resources participating in different processes. In this article, we present a multiagent enactment environment that incorporates the flexible allocation of resources but is also capable of handling various types of runtime exceptions. The benefits of adopting a knowledge-based approach are demonstrated based on a prototype implementation of an IT-Helpdesk scenario.