One of the best features of TFS is that the changes of the source code are documented not only by the changeset comments, but you can bind all changes to work items. TFS provides several work item types out of the box, however they are sometimes not perfectly suit our needs and require some customization.
Traditionally you can use the witadmin.exe command line tool to manage work item types. You can export their XML definitions and import them back to the server after you modified them. The benefit of this approach is that you can add the modified XML files to your source control to track the changes.
If you prefer GUI tools, you can install the TFS Power Tools which adds a Process Editor item to the Tools menu, which you can use to open the work item definition directly from the server:
In the next step you have to select which work item type you want to edit:
And you instantly get the list of the properties of the work item type:
If you don’t like that by default the Assigned To field shows all users of your server, then you can select this field from the and click the Edit button to modify it. In the second, Rules tab of the popup edit dialog you can see the reason of that behavior:
The problem is the VALIDUSER entry which refers to the Team Foundation Server Valid Users group. You can remove that and add the ALLOWEDVALUES rule instead, which allows you to configure the selectable list items. If you want to add user groups, you can refer to server-level groups in the [Global]\groupname form, and to the groups of the current project in [Project]\groupname form. For example:
You can find the detailed documentation of the available rules in the Rule Type dialog on the All FIELD XML elements reference MSDN page.
When you click Save the changes are directly committed to the server, and you may need to click Refresh in the Team Explorer window to let the Visual Studio client updated.