Hi Michel,
First off, Geert is right in saying that maintaining two versions of the same model in the same project is essentially impossible. EA is not built that way.
If you only want to see differences between old and new, baselines work well -- but only if you will never be making any changes to the old version. With baselines, the old versions are stored in XML format, not as regular models, so they're essentially frozen in carbonite. You can compare the current model to a baseline, but you can't change what's been baselined.
If you want to actively maintain two different versions, work in two projects instead. If you want to see differences between versions in different projects, again baselines work (you can move baselines between projects), but you have to set the structure up to support this before you begin modelling (GUIDs for the baselined elements must be the same in the two projects in order for EA to compare them).
1) is there a way to mark attributes / operations ?
A simple way is to set a stereotype "new" / "old" / "deleted". Note that EA will by default sort attributes/operations first in order of stereotype. You can change this behavior in the options.
(Of course, keeping "deleted" attributes in the model means you can't do things like code generation from the model without modifying the code generation templates, but I'm assuming you're not doing that.)
If you create your own UML profile, you can write a shape script which displays the attributes/operations differently depending on tagged values. I don't think you can set text colours, but you could get something like
+ [N] myAttr: Integer
+ [O] myOtherAttr: BooleanBut I wouldn't recommend this for a small model or if you're new to MDG Technologies; classes are complex beasts and overriding their default shape script isn't easy.
2) The question: " Is it possible to create relationships on the attribute / operation level That means to bind the corresponding attributes ?" meet other modeling techniques (e.g. bind some attributes between two whole different classes)
Yes, by using the "link to element feature" function (right-click the connector near the class where you want the connector to tie to a particular attribute/operation).
Note that this is an EA-specific feature not supported by UML. Thus the attributes and operations themselves cannot have relationships; EA just displays them in the diagrams in a way that makes it look as if they do.
In addition to all that, EA has a function called Gap Analysis Matrix. This works on two parallel model structures and identifies / records gaps, ie differences between them. It might be worth a look in your case.
Cheers,
/Uffe
