Framemaker 11 saving

Auto-save, and the .backup.fm files it creates are principally of use for document recovery after an FM crash. As the other contributors have already pointed out, it's not really an archival function, as the backup can be 5 minutes too old.

Another thing to know about auto-save is that some care is required if you ever need to rely on the .backup.fm file. Either open it directly, or preserve a copy of it. This is because whenever you open a .fm file, with auto-save enabled, FM immeditately over-writes any pre-existing .backup.fm file. Which is to say that, too often, just as you realize you need that backup file, it's now gone.

Back when I was in a production environment, we relied on the journaling file system instead.

The "Auto Save Every x Minutes" setting is in Edit > Preferences. I think it defaults to 5 minutes - what you set it at is up to you - depending on how often you're making changes, you can set it for shorter or longer intervals. For FM newbies, I always recommend getting a copy of Matt R. Sullivan's Publishing Fundamentals Unstructured FM 11 - it's old, but the concepts are still applicable to FM today.

You've turned on auto-saving and that's what's creating the .backup files - not your Save As action. You've conflated the two. Depending on what interval you've indicated in your Preferences, the backups will be updated then.