That's really an software architecture and development issue and wouldn't have anything to do with TFS. Take a look at the Enterprise Library http://msdn.microsoft.com/library/?url=/library/en-us/dnpag2/html/EntLib2.asp

TFS provides a work item tracking module, which can be used to track bugs. TFS provides an out-of-the-box experience to manually enter bugs via customizable forms. It also provides extensibility so another, automated system, can add bugs for tracking.

If another system were to detect bugs on a deployed system, you could use TFS and its extensible infrastructure to log/track those bugs. Then you TFS to query and report on those bugs.