Relation Between Modules Though The Core

I need to know if YII has feature to handle relations between modules based on core. I want to be able to add and remove modules without messing up the relations and dependencies between them.

I saw the ZURMO CRM (zurmo.org) was built on this kind of architecture and its based on yii, but it too complicated for me and I can’t find documentation about architecture of how it handles the module relationsheeps