An Interface List and the related diagrams provides a useful view of the complexity of the enterprise. The number and types of interfaces helps the architect understand how applications are connected and the level of complexity that exists. When these diagrams are drawn for baseline architectures the result is what people often term a Spaghetti diagram because of the numerous lines that connect applications together. This diagram is quite often the architectural evidence for what has been obvious in symptomatic failure of systems and the costs and problems associated with integrating new applications into the landscape.
Often these diagrams are drawn in a general purpose drawing tool by an external consultant and once they have served there purpose of highlighting the systemic problems are discarded. With Enterprise Architect there is the opportunity to create the diagrams and once the message is conveyed to management to reuse the diagram and the associated repository elements to begin the process of re-architecting the application integration architecture and untangling the spaghetti that has built up over years if not decades.