Visualizing and Analyzing Software Infrastructures

0 7 4 0 7 4 5 9 / 0 1 / $ 1 0 . 0 0 © 2 0 0 1 I E E E to help them study the existing architecture. At AT&T, these diagrams used to be created and updated manually, published annually, and distributed throughout the business units. The process of manually drawing system interface diagrams is tedious and error-prone: a simple diagram showing all the interconnections to a single system could take 30 minutes or more to draw, and the diagram often becomes obsolete before it is published. Moreover, it is not easy, through the draw-andpublish mechanism, to get a system interface diagram in real time based on an ad hoc query because the need for the diagram might not have been anticipated. For example, a manager in charge of reengineering billing operations across the company might want to generate diagrams that show the systems involved in bill calculations for more than 200 products and service offerings. Since these queries are unexpected and therefore the diagrams not published, manually producing all these diagrams could take a long time. This situation would likely delay the reengineering decision process. We built a system called Enterprise Navigator to let users make ad hoc queries about an enterprise software architecture and then automatically generate the corresponding system interface diagram in real time on the Web. Figure 1 shows a typical diagram EN generated for a particular ad hoc query. Each node represents a system, and each link represents an interface between the two connected systems. With EN, users can