The problem you are trying to solve is one of the areas addressed by the ITIL. In this particular case, mapping dependencies, you might want to look at a CMDB tool. There are a bunch of vendors in the space, and I'm guessing that you don't want to draw this diagram and forget it, but would actually like to have the information stay around for a while and be up to date. Your applications, hardware, customers, technologies, etc. are business entities. The relationships between them are what you are currently trying to map out. In general, if you can't get the tool to draw the diagrams for you, you can certainly get it to export the data (via a report option) in a format that you can feed to the graphics utility of your choice. Good Luck