to do a quick comparison, nowadays ships's crew is 90% crew and 20% officers. by officer I mean something around the ST equivalent of lieutenant.
and a great percentage of that crew do generally random service tasks, like carpenter (or general fix-up boy
), boatswain auxiliar, medic assistant or cooker.
comissioned officers do more specialized tasks like radio operator, engineer, storekeeper, or command.
thinking that you won't need a cooker, a storekeeper or a clean-wiper in the 23rd century, what would be the point of having 50 crewmen to attend, say, an engineering section that with automation and stuff can be run by 20 (fulfilling the needed crew per shift)?
shuttle pilots? yeah, maybe, perhaps 10 or 15 working 4 or 5 per shift, not too many in the end.
scientists? that can be a major need, but each department can run with, say, a chief, two or three adjunts (Crusher/Ogawa? LaForge/Porter?), two assistants and maybe 10 crewmen? per, say, 10 departments counting astrophysics, biology, medicine, and some others? a gross of 150 officers to say the most?
operations? maybe the biggest one, including transporters, operations, engines, security, cargo and stuff. using the same system than science, that would count around 350 people.
what would give an estimated crew count of 500/600 people.
if the Ent-d crew count was around 1020 crewmen and passengers, that would fit.
there should have been more on-screen action of civilians in TNG and less officers, since most of the cre in the ten forward were starfleet crew
also, most of the action passes when the main crew is on shift, what would be around 0600 to 1400 and 1400 to 2200
so it's possible that at least 6 hours a day the bridge and most of the ship is crewed by Lt.Cmd's or Lt's.
...or androids, for that matter
