Managing modern information systems becomes increasingly complex. Therefore, the need for flexible mechanisms which assist system managers is evident. Management policies are means to control object behaviour. Considerable work has been done on the specification and classification of policies, but their enforcement is still an open research topic. In this paper we propose an event-driven approach to policy-based management, where a manager delegates policy enforcement to an agent. We introduce a policy controller object, which holds management information in the form of rules and controls the behaviour of arbitrary objects. We also present performance results and an example using the introduced concepts which is implemented on the ANSAware distributed platform.