Introduction
In my current organisation, we have many desktop and web applications all feeding into each other at some point. When looking after older applications or creating new applications, it's proving very difficult to try and remember which system rely on other systems in order to work. I'm not talking about software dependencies like DLL's and images, I'm talking about entire systems like a Finance system dependant on the HR system etc.
My Question
Which is the one best way to track how one entire system is dependant on another?
The answer can suggest either a method of doing the above, a software package or documentation techniques.
In my particular case, Many means over 20 web and desktop application over a dozen servers.
I would say to clearly state that on your architecture design document. There are some good tools for this like Enterprise Architect. This tool allows you to create diagrams using the UML standard for describing these dependencies in a clear and visual way.