This article develops a reference model for decision modeling using Decision Model and Notation (DMN) based on the example of sales processes. While Business Process Modeling and Notation (BPMN) is widely used to visualize sales processes, the underlying decision logic rarely remains formalized. To close this gap, the DMN reference model shows initial results of decision points with reusable decision tables along the seven phases of the sales cycle (prospecting, preparation, approach, presentation, objection handling, closing, and follow-up). These can be used by practitioners as a blueprint for modern data-driven sales approaches (e.g., automation, artificial intelligence, omnichannel marketing). Further research will focus on expanding the phases and models and measuring the positive impact on decision-oriented performance improvements.