ERD Generator for Dynamics CRM 2011/2013 is a Windows Form application that is can be used for Dynamics CRM 2011 or Dynamics CRM 2013:
For CRM 2015, Use following link: https://dynamicsofdynamicscrm.wordpress.com/2015/04/16/new-versionerd-generator-tool-for-crm-2015/
Here is a video to see how this will work:
Just download the above .doc file and rename it to .zip and run the tool.
This tool allows you to build ERD (Entity relationship diagrams) that are dynamically updated based on the published CRM entities and Fields. You can pick a source entity and build ERD around it. It generate a VISIO output but also lets you pick CSV to document Entity relationships.
It generates a CSV having details like:
It generates ERD in VISIO:
Visio legend below:
Hope it helps!
Check this out