This is the 7th an final post in a series on Fatigue in the Workplace. Previous posts on this topic have covered the impact of: (1) education, (2) start times, (3) shift length, (4 consecutive days of work, (5) rotating shifts, and (6) employee preferences. Today's post will address the role of overtime in employee alertness and fatigue.

Let's face it, overtime disrupts people's lives. They have plans that get changed at the last minute. They are forced to work when they had other plans. How do they respond? Forfeiting sleep is one of the most common ways employees try to recover time off lost to overtime.

How much overtime is too much is a difficult question to answer. Most companies feel that an annual average of between 5% and 15% is about right. However, there are a lot of considerations other than alertness that go into finding the perfect amount for any operation. You may wish to read a more complete article on the impact of high overtime (http://www.shift-schedule-design.com/preview/uploaded/files/Overtime%).

Here is a quick summary from the above referenced article. "Our surveys of shiftworkers show that, on average, they get 21% less sleep time on the days they work than the days they are off. When employees work lots of overtime, they don't get time off to recover or catch up on their sleep. This, in turn, can lead to fatigue and reduced alertness. Managers simply cannot ignore the possibility of increased safety and quality incidents under these conditions."