Hi,

Let me start by saying that Astah is by far the best UML modeling tool I have ever used. I especially like the synchronization between diagrams and the alignment features.

That being said, I do have some improvement suggestions:

For class diagrams:
- Support for N-ary associations.

- The ability to show the class visibility visually (+ for public etc.), in front of the class name.

- The ability to show both a navigable arrow and an aggregation/composition symbol for an association end. (It is already possible to do this for non-navigable associations, i.e. cross combined with an agg/comp symbol)


For deployment diagrams:
- The ability to properly nest nodes (moving the outer node should also move the inner node)

- The ability to add Artifacts to Nodes. I think that using Components in a deployment diagram was the old UML 1.x way, in UML 2.x you should use Artifacts instead.