ABSTRACT
Shi– work involves work outside the daytime hours of approximately 7:00 am to 6:00 pm. According to the U.S. Bureau of Labor Statistics, almost 15% of full-time workers (or 15 million Americans) work on evening, night, rotating, split or employer-arranged irregular shi–s [1]. Both societal needs and economic factors drive the use of shi– work. Society needs critical services around-the-clock for police and re protection, health care, transportation, communications, public utilities, and military service. Other industries require workers around-the-clock because their production processes and operations need to be continuous to optimize capital investment in machinery, or the manufacturing process cannot be interrupted for production reasons. As a result, certain types of work are likely to always require shi– workers.
