Code deployment DEV -> QA -> PROD

Our company requires a traditional code migration from DEV to QA to PROD and we have been using TFS for code revision control and wondered if and how this might work for Ignition. I am familiar with traditional gateway backups and project backups but had some trouble trying to load a project file from one environment to the next (maybe because I had them named differently so I could differentiate if I had more than one environment open). Any suggestions on how to manage deploying project changes to a prod environment (smoothly, maybe even scripted) witout having to use the designer or causing any downtime to the application?