Systems Analysis and Design is a core component of most information systems curricula, and generally includes coverage of process modeling with data flow diagrams. In order to relate process modeling to something with which all students are familiar, the content of a traditional Systems Analysis and Design course can be supplemented with an ontological framework. This manuscript proposes that an ontology from accounting literature (REA) be used to supplement traditional modeling approaches. The REA Ontology incorporates elementary accounting concepts familiar to many business students, and as a consequence makes contextual learning possible. This manuscript points out several synergies between the REA Ontology and data flow diagrams, and notes that the contextual learning factor enhances student learning. As a result, students are able to develop an efficient and enriched mental concept of data flow modeling and the business processes the models seek to capture.