Enterprise Resource Planning Systems (ERP) are very large and complex software packages that run every aspect of an organization. Increasingly, ERP systems are being used in higher education as one way to teach business processes, essential knowledge for students competing in today's business environment. Past research attempting to measure learning business processes with ERP has been inconclusive and lacking in rigor. This paper reports on a comprehensive research study that uses a critical realist approach to measure business process learning from experiential ERP. Using a business simulation game as a proxy for understanding business processes, students from a US undergraduate program in three separate classes, one using ERP experientially, are assessed both quantitatively and qualitatively. The data analysis uncovers a causal mechanism for learning, complemented by an understanding of the factors that trigger or suppress that mechanism in particular cases. The results validate the efforts of those using ERP in the classroom, and reaffirm other educational business school endeavours to teach business processes, with educational implications as follows. First, before attempting to learn business processes, students must have an understanding of core business concepts. Second, hands-on experience of ERP systems indeed helps students understand business processes. Third, students are showing that they can use the knowledge gained in university classes and apply it to making business decisions. Fourth, students should be encouraged to use all information possible for making business decisions instead of relying on their personal understanding of today's current market or on their own business intuition.