Compliance is a critical enterprise management concern, particularly in business process-oriented organizations. Compliance measures are often implemented using policies, of which decision-making requires high independence from implementation logic and high flexibility. This paper motivates the use of an event-centric approach for modeling policy decision-making. The authors introduce an event ontology part of a policy and rules ontology for compliance modeling and enforcement. The policy and rules ontology is able to take decisions depending on the compliant state of an enterprise model.