This is a correct behavior. In TDM, key attributes migrate from parent table to child table automatically when you create a relationship between them.
You don’t have to create the attributes in child tables manually. TDM will do it for you - as soon as you add the relationship.
When keys are duplicate, you can use the FK Mapping feature.
Please see the Help file | Index tab and type ‘fk’. Please see the following topics: foreign keys and fk mapping.
Also, I recommend you to watch the following flash movies:
Create ERD - http://modeling.inside.quest.com/entry.jspa?externalID=1667&categoryID=158
FK mapping - http://modeling.inside.quest.com/entry.jspa?externalID=1668&categoryID=158
and others at:
Please sort the movies by Title - Ascending order and start with the ‘Getting Started’ movies.
If you have any questions, please write me back. Thanks.