I have been modeling application landscapes in the ArchiMate language and think it is a vehicle you should consider to use when you are an IT architect. It offers a good toolbox of enterprise architecture concepts and a set of rules on how to stick them together. You can try it out with the open source Archi tool, which offers all basic functionality to work with ArchiMate. There are other more extensive and expensive ArchiMate tools, to be found on the ArchiMate site. Archi works fine for me up to this point however.
I use Archi mainly for “IT geography”, laying down my “IT archaeology” findings in an applications map. Extending the applications map with a processes map and thus linking the process and application levels of your enterprise architecture is also possible. Further down the architecture stack you can also model and relate to the technological situation.
The maps are very useful in communication. A picture really says more than a thousand words and I can get to the point quickly in discussions about which architecture pattern or mechanism to use to solve a particular architecture issue. ArchiMate also helps to get the ambiguities out of the discussion. Because the maps can be understood by both business and IT (if not then maybe they should not join the discussion at all…) and because it is a formal language, it leaves little room for interpreting the situation differently. I can be reasonably certain that everybody understands each other and that the risk of surprises in working out the described solution is small.
I still have to investigate how products made in the ArchiMate language relate to process and architecture modeling in Aris. IDS Scheer does offer a tool, ArchiMate Modeler, that combines Aris and ArchiMate, but unfortunately it is not open source.