I think he's asking if an automated furnace setup is not allowed, much like an auto farm. But you simply place coal/fuel in one chest and it gets automaticaly distributed to x amount of furnaces, usually via a minecart with a hopper in it, and same goes for the items you want to smelt ie. ores.
Autosmelters still require manual input of fuel and items. So yes it's allowed and has been used by players in the past. As long as you don't connect it up to some farm.