Shari yn Yem is a Pandronian drill instructor who runs the Cerritos crew through holodeck training scenarios to secure her own job.
Shari yn Yem is a Pandronian Starfleet drill instructor sent to the Cerritos in I, Excretus after friction grows between the lower decks crew and the senior officers. She oversees a series of holodeck drills intended to build better understanding among the crew.
The whole crew fails except Boimler, who obsessively reruns his Borg drill seeking a perfect score. The officers suspect the drills were rigged to bring them together, but Shari admits they were designed to secure her continued employment. When the crew proves its abilities, she changes their score to passing.