title: How to handle updating an Enterprise Architect UML model with XMI import
body: <p>I use Enterprise Architect v. 12 for designing a new application. Now I'd like to add reverse engineering of the created source code into our development process. I would like to create an EA project with two Models (root nodes):</p>
  
  <ul>
  <li>Diagrams: Shall contain all of our hand-drawn diagrams. The diagrams shall use classes etc. from the Implementation Model</li>
  <li>Implementation Model: Shall be updated at scheduled intervals by exporting an XMI file from our development system and importing the XMI file into the EA project</li>
  </ul>
  
  <p>This seems to be a rather common scenario to me. However, when I try this I run into the following problems:</p>
  
  <ul>
  <li>When I import an XMI file in to the Implementation Model I get a new package "Root" with several sub-packages (and classes etc.). This is due to the structure of the XMI file. When I import the same file again, the EA importer creates a new package "Root" below the Implementation Model next to the existing package. I.e. it doesn't update the model but sort of duplicates it.</li>
  <li>When I now delete the old Root package the hand-drawn diagrams in the Diagrams model get empty, i.e. all contained elements vanish. This is a consequence of my first issue.</li>
  </ul>
  
  <p>Is it possible to tell the EA XMI import that it shall update an existing package? The <a href="http://www.sparxsystems.com/enterprise_architect_user_guide/12.0/projects_and_teams/importxmi.html" rel="nofollow">official EA documentation</a> says "When you import an XML file over an existing Package, ALL information in the current Package is deleted first..." but this somehow doesn't work in this case.</p>
  
  <p>Do you have any advice on how to handle roundtrip engineering of an UML model with EA in general?</p>
  
  <p>Kind regards,
  Valentin</p>