mvn can build the ear file for you and manage the versions of the ear's modules and dependencies.
It can also do releases, which is automation of creating a tag (an immutable version) in your artifacts repository which helps say if you have to do a prod fix while other work is currently going on the main code base.
You would have to through some tutorials (posting in these forums if you get stuck) to start using maven in your projects.
I'm not dead! I feel happy! I'd like to go for a walk! I'll even read a tiny ad:
Building a Better World in your Backyard by Paul Wheaton and Shawn Klassen-Koop