Comment by i_am_proteus

And then there are drills. Simulated equipment failures, fire, flooding, etc.; all of the alarms sound as if it were real, and the crew responds as if it were real (except that no extinguishers are discharged, no SCBAs lit off, no hoses pressurized). Scheduling drills without detrimental effects on the crew's sleep, but still making the drills a surprise and a challenge, is (like the reactor) critical.