Large and Small Crews
A starship’s base frame determines the minimum and maximum number of crew members needed to operate that vessel. A starship without its minimum complement can’t be flown. However, when a large NPC starship with its full complement enters starship combat, each individual crew member doesn’t take a regular action—it would take hours to resolve a single round! In such cases, usually on Large or larger starships, most roles simulate entire teams of personnel. The number of crew members required to assist a single officer who wants to attempt a check in that role is listed after the role’s name in a starship stat block. This number varies between starships, and some vessels might have a crew large enough to allow multiple checks for a single role—for instance, a dreadnought might have several teams of engineers or gunners.
Source
Core Rulebook pg. 316