Alan Sims was a Starfleet officer in the 24th century.
In 2353, he was listed as a Starfleet Operational Support Services officer on a directory placard in Starbase 32, Maxia sector. His office was located in room #75260. (TNG: "Violations", directory)
In 2371, he was listed as an Yard Engineer on the dedication plaque of the USS Voyager. (VOY: "Caretaker", dedication plaque) He was still aboard the USS Voyager when the ship was forcefully brought to the Delta Quadrant by the Caretaker.
In 2372, as a lieutenant, he was listed on the Planetary Geosciences Division duty roster. (VOY: "Parturition")
In 2374, he was listed on a crew manifest. (VOY: "The Killing Game", crew manifest)
This character was only mentioned in writing.