I, Excretus

Friction between the lower decks crew and senior officers grows when several lower decks crew members are accidentally left behind during a spacewalk repair mission. Shari yn Yem, a Starfleet drill instructor, oversees a series of holodeck drills to build better understanding among the crew. They all fail their assigned drills except for Boimler, who achieves high marks but obsessively reruns the drill in an attempt to achieve a perfect score. Mariner and Freeman's disagreements cause the team to fail a simple docking drill in record time, and they come to better appreciate one another. They suspect that the drills were rigged for failure to bring them all together, but Shari reveals that this was actually a bid to ensure her continued employment.

Summary from Wikipedia, CC BY-SA 4.0.