Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and have raised production efficiency in various industries.

• Afatigue among shift workers, and have raised  
• Bfatigue among shift workers, and raised  
• Cand fatigue among shift workers while raising  
• Dlowered fatigue among shift workers, and raised  
• Eand fatigue among shift workers was lowered while raising