Shift Work and Circadian Rhythms

Excerpts taken from "Managing the 911 Center, A Book for Public Safety Communications Managers" 3rd Edition
Written by Eric Perry, ENP


Circadian rhythms are the biological clocks that regulate all life. Proponents of circadian rhythms believe that these clocks do not follow our twenty-four-hour day but rather a day about twenty-five hours long. Since humans should really be on this circadian day, we are continually thrown off our natural cycle by living our lives in twenty-four-hour increments. There is a great deal of interest in this science of chronobiology. The medical community was initially skeptical, but today there is more acceptance to how biological clocks affect our functioning. Our internal clock tells us when to eat, sleep, look for food and process it. Our metabolisms peak and ebb throughout the day, and these changes accompany biological variations in heart rate, temperature, blood pressure and others. They follow a regular predictable pattern, with the most noticeable ebb occurring during sleep. Circadian rhythms are reset by light, so theoretically, when light hits your retina, your internal clock is reset. The implications of ciradian rhythms go beyond our basic biological functions and have been linked to sleep disorders, jet lag, depression, and a host of other maladies. If a twenty-four-hour day forces the human body off its natural twenty-five-hour clock, then having to work the night shift must throw it into complete disarray.

Some PSAPs use variations of traditional eight, ten and twelve-hour shifts. For those who are bent on twelve-hour shifts, who cannot bear to give up four days off in a row, there is some hope. Often, shifts are modified such that a person works a month of days, on the four-on, four-off cycle. This means four days in a row working 0700-1900, followed by four days off. Then another four days of 0700-1900. This is done for four weeks. Then the employee changes to a month of nights, on the four-on, four-off cycle. This means four days in a row working 1900-0700, then four days off.

There are pros and cons to twelve hour shifts. There seems to be a general preference, by those who have done both, for the latter arrangement. The consensus is that there is more of a routine, and that the first day off is not necessarily spent sleeping.

The simple fact is that human beings are not designed to perform shift work. We are supposed to get up when it gets light, go to work, come home and go to bed when it gets dark. We are supposed to have a good, restful sleep and when the sun starts to rise, get up again. Unfortunately, 911 was not around when we were evolving such natural rhythms.

Not so long ago, everyone worked eight-hour shifts. Today shift systems use eight, ten, twelve and twenty-four hour systems with many combinations and permutations. There are no right or wrong shift systems, only those that are not as bad as the others. Good shift systems allow your dispatchers enough time to rest and recharge between work periods. This means rest periods and lunch breaks at scheduled times. Good shift systems allow for flexibility in overlapping human resources during busy periods. Shift systems should enhance your operational effectiveness, not tip it over.

In some operations, where the 911 facility is an extension of another emergency service, communicators and field personnel operate as one team. The communicators are actually part of the same shift, platoon or watch. This sort of a "oneness" system can cause some problems, but if your agency has been doing things this way for some time, it will be very difficult to change. Still, there is no strong case for keeping the same dispatchers tied to a particular shift of field personnel. The argument presented by those who support the oneness system is that the team approach is the best approach and that dispatchers are part of the team. But the very reasons put forth for the oneness system create potential operational problems.

One of the first things that becomes apparent under the oneness system is that each shift tends to operate with its own rules. If you have four shifts, then you have almost four different agencies. People being people, they will create their own way of doing things, introducing unwritten SOPs that will be unique from one watch to the next. This creates an immediate bias in the area of communications operations. For example, by "knowing" the best people for certain types of calls, the stage is set for communicators to be biased and selective in their dispatching. Have you heard the story about the person that could do almost everything? She was very busy. Then there was the person who could not do anything. She was bored. Both collected their pay on the same day, and the pay for both was the same.

In a situation where an automated CAD system assigns calls according to available units, does the computer know quirks and personalities? Another example: the consolidation or amalgamation of communications facilities that serve many independent agencies over a large geographic area is nothing new. If the arguments put forward by the oneness supporters were sound, centralized dispatch facilities would have to ensure that every agency served had the same group of people working the same shifts at every location. It would also mean that airlines should schedule the same pilots so that tower controllers get to know all the pilots coming and going.

A communications facility does not have to be married to a particular watch. A healthy overlap of a shift of dispatchers with a group of field personnel is actually better for the operation. It promotes professionalism by reducing bias and prejudice. It encourages adherence to SOPs, and creates both variety and stability in the overall operational work force.

Some people view twelve-hour shifts as the most unkind system of scheduling dispatchers. One of the reasons that agencies use twelve-hour shifts stems from wanting the shifts to track the field personnel on their shifts. But twelve hours in a communications facility is completely different than twelve hours anywhere else. Inside the communications center, things do not stop. The center is a funnel that catches everything and then redistributes a portion to a team of field personnel. The work received by field personnel is a fraction of the overall work processed by the center. Twelve hours working in a funnel is not the same as twelve hours working with fractions. On the road, you can frequently escape the mayhem. In the center, you cannot.