Serviceability as in it's function or use? Space has no friction to have the shuttle slide off with movement. Good example of this is Any EVA in orbit, the Astronauts don't fly off or get peeled away from the ship. Grav plating and magnetic clamps would secure things on deck. Intention the ship wouldn't be going to high impulse or warp with things here. Just during orbit or in dock/station.
As for function it is mostly intended for anything that wont fit height wise through the main doors. It is also used for staging materials for repairs or other things where you need a staging deck for receiving or departure of cargo and large objects.