Merging of changes with EA

[AlexY]

Hello All,

I am looking for advice about how to approach an IT transformation modeling project.
The goal is to model and visualize a transformation of an existing IT system; the existing system needs to be "reverse-engineered" first.

Simplified, the process looks as follows:
(1) Build a model of current state of the system ("current" model);
(2) Based on the “current” model, create a model of target system ("target" model);
(3) Create a gap analysis report (differences between the “current” and the “target”) which will be the source of tasks to perform the transformation.

The first idea coming to mind is to apply EA baselines/compare/merging features:
- Create a "current" model;
- Create “current” baseline it in EA;
- Create the "target" model from the “current”;
- Use EA diff tool to show differences between the head the “current” baseline to create the gap analysis.

Unfortunately it is not that simple; as the “precision” of manual "reverse-engineering" is as such, that I will probably never have a 100% complete/accurate "current" model. So, I will need to fix the "current" model as I discover inconsistencies between the model and reality, and I will need to merge the changes in the “current” model into “target”.
This requires comparing between past baselines of the “current"  model to identify changes and merging the changes into the “target” model. This is a classical task in software engineering, but I do not see how to accomplish this with EA diff tool.

What is the right way to approach such a project with EA?
Can you please suggest the state-of-the art approach how to do this with EA?

Thanks a lot in advance!

Alex.