Being understaffed creates a myriad of problems, not the least of which is the burden it puts on the staff that is on board. when you don't have enough people working a shift, everyone has to do a job and a half or two jobs or three, juggling more than they ought to. This means that some of the work just cannot be given the time and attention it deserves. It also means that employees are over taxed and burn out much faster, faster than self care can mitigate. Logistics are harder, who can cover the shifts and what happens when someone is sick, god forbid they take a vacation. If the employees are hourly it also likely means overtime, which means it costs more to have less people if there is more work to be done. All in all it ought to be a top priority to be fully staffed.