Order acceptance decisions have a significant influence on the short- and long-term performance of a firm. Firms, therefore, should make complex order acceptance decisions with regard to their organizational goals in an effective way. Models are called for to provide insight for decision-makers in developing proper strategies for order acceptance. This research presents an agent-based model to support order acceptance decisions in a multi-plant enterprise, particularly incorporating buyer-seller negotiations. The negotiation process is conceptualized in three phases, pre-negotiation, negotiation, and post-negotiation, taking into account salient viewpoints on making order acceptance decisions. The conceptualization and the developed model not only provide valuable insights into the nature of negotiation in a supply chain setting, but also contribute to the understanding of strategy development for order acceptance.