Every object in DAD has a history.  This logs every user operation that has affected the object from creation to deletion.

This is the history for a component.  Note how it logs all changes.

Connectors also have individual histories. 

 There are history and other related features to assist you in managing the control of document revisions.  So each document has a history as shown here.

You can request a list of the changes to the objects in the document since it was issued as shown - 

Each object lists the documents it has been published on.  So if you modify a component such as this one below you can see what documents might be affected and then decide whether to regenerate them or not.  

There are a range of utilities to handle the history data for the complete model.