Nowadays enterprise architecting and business process engineering are almost synonymous to diagramming. Diagrams have many benefits and are sufficient for many situations. But as the number of diagrams and their types grows, they overlap and evolve, then it becomes hard to maintain a collection of interrelated diagrams, even with the help of a common repository. Besides the very nature of enterprise architecting requires a lot of matrices (goals-processes, capabilities-processes, processes - applications). The paper presents the multi-representation approach for enterprise architecture model development and maintenance. Classifications and matrices are the basis of this approach and support knowledge structuring and integration. The ORG-Master tool joins classifications and matrices with traditional diagram-based technologies. The paper pays special attention to the role of classifications and matrices in integrating business processes into enterprise architecture.