From Jeff Tondt
Visio is one of the most popular tools for creating diagrams that describe effective systems and processes. In every project in which I participate, when it comes to documenting what you did I always have to create a diagram where I defined architecture, server configuration, network, etc. A picture is worth a thousand words and Visio is the tool of choice in these documentation tasks.
With SMSMap you can read FEP components and ConfigMgr/SMS site roles through COM and automate Visio to draw a diagram of the hierarchy including the FEP SQL Reporting Server, FEP Data Warehouse SQL Server, and the FEP Reporting Component.
Developed by Jeff Tondt this free utility is available at http://www.tondtware.com and works on ConfigMgr SP2 / R3 and down to SMS 2003. Seeing the whole FEP/ConfigMgr hierarchy as a picture can help you quickly understand how your infrastructure is laid out. This handy tool automates creation of your infrastructure documentation and frees you up for other Forefront product installations.
Some screenshots of SMSMap: