Changing the scope of the AssignedTo field in TFS 2012 Work Items

By default, Team Foundation Server presents all "available or existing" users when you assign a work item to somebody. Of course, it's possible to customize TFS to display only members of one or multi groups in Assign To field.

To do that...

1. Open Visual Studio (with Team Foundation Server Power Tools).
2. Go to Tools / Process Editor / Work Item Types / Open WIT From Server.
3. Select your Team Collection and your Work Item Type.
4. Select and edit « Assigned To » Field.
5. Add a new Rule « AllowedValues » and a new value « [project]\Contributors » (see picture below).
6. Close all dialog boxes.
7. Save the WIT file to the server (CTRL+S).

Note the [project] should be as is and not substituted for your own project name.