(With many thanks to Atomic Rocket and Raymond McVay of Blue Max Studios, whose Mission Control Model I drew upon heavily for inspiration while working out this alternate-style command structure.)

Command Roster: The command roster of an Imperial starship, civilian or military, looks something like this – with variations, as specialized ships require:

(Above this entire structure, potentially, a Mission Commander (Admiral, Commodore, etc.), in charge of a task force of multiple ships.)

Flight Commander: The overall director of the operation, the big boss. In charge of everything.

1. Flight Executive (Exec)
   In charge of supervising all exterior and interior communications (the bridge between the ship’s Shipboard Information System, the ship’s crew, other ships, and the other departments; the equivalent of a Naval vessel’s executive officer, without their administrative role, which is the responsibility of the Flight Administrator. Since there is only one Flight Commander per ship, the officers in the role of Exec serve as officer of the deck when the FC is not present; other posts tend to have a first, second, and third occupying them.
   1. Spacecraft Communications (Comms)
      Communicator between the spacecraft and other ships or stations; also in charge of tangle communications and cryptography.
   2. Docks and Locks (Locks)
      On ships large enough to have other vessels docking to them and thus requiring the eponymous department, in charge of docking cradles, airlocks, shuttle bays, and the associated requirements in terms of atmosphere management and body shops. If the ship has no dedicated Small Craft Operations officer, also looks after what small craft there are, if any – i.e., carried cutters.
   3. Small Craft Operations (Air)
      On carriers (or megafreighters using the LASH model), in charge of carried interceptors, lighters, and other small craft and their operations.
2. Flight Director (Flight)
   In overall charge of navigating the ship and engaging in flight operations as the FC and/or exec direct.
   1. Pilot/Sailing Master (Helm)
      Actively pilots the spacecraft, performing maneuvers and managing the attitude control systems.
   2. Astrogation and Guidance (Guidance)
      Navigates the spacecraft, operates the flight computers – and monitors their continued correct operation – and inertial/star tracking platforms, maintains position records, plots courses and orbits, and so forth.
   3. Relativistics (Time)
      Manages the ship’s timebase and maintains the systems that properly compensate for relativistic variation, including maintaining lock on the empire time/wall-clock time differential and other reference frame corrections.
   4. Sensor Operations (Sensory)
      In charge of all non-navigational sensors (and non-navigational uses of the navigational sensors), and maintaining the current picture of near space; this requires considerable creative interpolation to overcome light-lag, which is Sensory’s job.
   5. Tactical/Payload Operations (Guns – even on non-military vessels)
      On military vessels, in charge of weapons and firing them at the enemy; and defenses and using them against incoming fire. On all vessels, in charge of operating any and all modules plugged into the ship and any “active cargo” being carried.
   6. Data Operations (Data)
      In charge of setting up whatever programs or other complex computations the rest of the bridge officers need, ad hoc, critical path management, resource allocation, the ship’s library, etc.
3. Flight Engineer (Chief)
   In overall charge of all engineering systems.
   1. Propulsion Engineer (Drive)
      In charge of the entire spacecraft propulsion system, from propellant to nacelle, including navigation hardware. Also responsible for tracking remaining Δv capacity.
   2. Power Engineer (Power)
      Responsible for power plant, power plant fuel supply, electrical systems, other power systems, and also monitoring internally-generated radiation if relevant.
   3. Thermal Engineer (Heat)
      In charge of all thermal control systems, including but not limited to heat sinks, radiators, heat pumps, and other thermal transfer systems.
   4. Data Systems Engineer (Comps)
      In charge of the ship’s primary data systems, including the Shipboard Information Service.
   5. Mechanical Arms and Non-Sophont Crew Engineer (Mechs)
      Responsible for the maintenance of all the ship’s robotic arms, robots, cyberswarms, and associated systems.
   6. Sensory and Guidance Systems Engineer (Systems)
      Responsible for all the sensory and guidance systems hardware; flight computers, laser grid, telescopes, radar, star-tracking platform, etc., etc.
   7. Environmental Engineer (Life)
      In overall charge of all life-support systems.
      1. Closed-Ecology Life Support Systems Manager
         Responsible for the environmental systems; heat, air, water, recycling, and the ongoing provision of same.
      2. Galley Manager
         Responsible for the carniculture vats, hydroponic systems, and other on-board food production equipment, as well as the galleys and other means of cooking it, and the slop chest.
   8. Auxiliary Systems Engineer (Aux)
      Responsible for maintenance and upkeep of all other ship’s systems, and general maintenance and stores, including the ship’s locker.
4. Flight Administrator (Admin)
   In charge of all administrative details, ship’s paperwork, and discipline among the other departments.
   1. Cargomaster (Cargo)
      In charge of loading and unloading cargo; also in charge of ensuring that the cargo is stored in a proper balanced manner, center-of-mass-and-moment-of-inertia-wise.
   2. Purser
      In charge of self-mobile cargo; i.e., passengers and all their foibles.
   3. Flight Surgeon (Doc)
      Medical officer. In charge of dealing with disease, injury, ship’s cleanliness, and environmental radiation.

The usual bridge crew/command conference, in which the posts are filled for each watch, consists of the Captain/Flight Commander, the Flight Executive and his immediate subordinates, the Flight Director and his immediate subordinates, the Flight Engineer, and the Flight Administrator.

Lesser positions may be merged, either with each other or their superior position, on smaller ships.  Minimum crew size for anything above a small craft is four; one Captain/Flight Commander, three Flight Directors (one per watch, assuming necessary sleep patterns; only one digisapient FD would be permissible, for example) – if maintenance and operational requirements can be met.