A new “Value Area” field to all work items has been introduced in TFS 2015, that appears on a backlog, that is: Epics, Features, and (depending on your process template), the field also appears on Product Backlog Items, User Stories, and Requirements.
The Value area has two values:
The default selected value would be Business for all Epics, Features, and Stories.
To create an Architectural Epic, Feature, or Story, set the value to Architectural.
With this functionality, now you can also define Architectural Epics, which in turn break down into Architectural Features and Stories, allowing you to track your architectural roadmap across your organization.