April 2019, Vol. 246, No. 4


Controller Alertness over the Shift

By Michele Terranova and Alicia Gibson, Pipeline Performance Group, LLC

How alert are your controllers at work?  Are they wide-awake, exhibiting signs of liveliness and enthusiasm at all hours of the day and night? Being alert and vigilant on the job is essential to the controller’s job. Controllers spend over one-third of their time monitoring systems.

It is important that they are vigilant during this time in order to monitor current system state, predict future states, and anticipate the potential for abnormal events. Alertness is key to situation awareness, decision-making and communication.

Research shows that shift work is difficult on the body. Shift work is especially difficult if the company is not effectively managing the things that cause fatigue, such as the shift schedule or ergonomics in the control room. Shift work is also difficult, if controllers are not effectively managing the factors in their own lives that affect fatigue, such as rest, diet or exercise.

During the last eight years, we have assessed workload and alertness in the pipeline industry. More than 750 controllers from 77 control rooms participated in the 254 workload assessments we conducted from 2011 to 2019.  These controllers represent control rooms in the United States, Canada and Australia. They are responsible for gas transmission, gas distribution, hazard liquids or gas and liquids pipelines. (Figure 1).

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We asked controllers to rate their alertness each hour during a 12-hour shift using the Pipeliner Alertness Scale. Controllers use a 9-point scale to self-report their drowsiness. The scale was adapted from the Karolinska Sleepiness Scale (KSS) from the Karolinska Institute in Sweden.

Karolinska Sleepiness Scale

  1. Extremely alert
  2. Very alert
  3. Alert
  4. Rather alert
  5. Neither alert nor sleepy
  6. Some signs of sleepiness
  7. Sleepy, it’s no effort to stay awake
  8. Sleepy, some effort to stay awake
  9. Very sleepy, great effort to stay awake,
    fighting sleep

More than 750 Controllers submitted hourly alertness ratings throughout four 12-hour shifts. The assessments took place during an eight-year period in 77 control rooms in which 62,376 hours were rated by controllers.

A key finding in analyses of the data is that overall, over the course of their shifts, controllers are mostly alert. In fact, controllers report being alert 82% of the time extremely alert (21%), very alert (28%) or alert (33%)).  Sixteen percent of controllers report lower alertness ratings (rather alert (8%), neither alert nor sleepy (5%) or some signs of sleepiness (3%)).  Only 2% of controllers report being sleepy (Sleepy, it’s no effort to stay awake (1%), sleepy, some effort to stay awake (0.8%), or v sleepy, great effort to stay awake, fighting sleep (0.2%)).

Not surprisingly, the 82% controller alertness breaks down between day shift and night shift. Controllers on day shift report being alert 44% of the time, while on night shift this is 39% (Figure 3).

A Controller may come into work at the beginning of the shift feeling extremely alert, but as the shift continues alertness levels tend to drop. Then, in the last hour or so of the shift, alertness increases as activities at end the shift increase.

So, what can be done to counter fatigue? Fatigue needs to be addressed by both the company and the controller.  The company, for their part, must schedule shifts to provide the opportunity for controllers to get eight hours of sleep, taking into account their commute times.

The company should also provide training about shift work and fatigue management strategies. Ideally, the controllers then apply these fatigue management strategies on the job and in their personal lives. We asked over 1,000 controllers in the United States, Canada and Australia whether their shift schedule is designed to allow them the opportunity to get eight hours of sleep.  Less than two out of every five controllers strongly agreed that their shifts provided this opportunity. Fifteen percent of controllers surveyed were either neutral or disagreed that their shift schedule provided the opportunity for adequate sleep.

Controllers were also asked whether their company provided training about shift work and fatigue management strategies. About four out of five Controllers agreed that their company provided training. Nineteen percent, or one out of five Controllers, are not receiving fatigue management training.

Once a company provides fatigue management training, controllers are responsible to take these strategies and apply them to the job and to their personal lives. Almost one-third of controllers surveyed are not applying these practices to the job or their lives. in fact, one- fourth of all controllers report they are not always alert and vigilant on the job.

It is possible that participating in a computer-based fatigue training course once a year is not compelling enough for a significant portion of the controllers to effectively apply fatigue risk management strategies. 

The data suggests that additional efforts by the company and the controllers, such as offering various types of fatigue training, more frequent discussions (one-on-one as well as in team settings) about fatigue risks and possible mitigation strategies, exploring various fatigue countermeasures, and fostering an environment that allows controllers to feel comfortable discussing and helping each other with fatigue-related assistance and possible mitigation solutions may be necessary to improve the situation in many control rooms.

Common fatigue issues that controllers report during their shift are: feeling generally drowsy and fatigued, feeling ‘rough’ for the first few days when changing shifts, drinking more caffeinated beverages on the night shift, and finding it difficult to get undisturbed periods of sleep between shifts.


Controllers surveyed said the following works to help them deal with fatigue during the shift (in order of frequency of response):

  • Predictable work schedule
  • Adequate time off
  • Enough rest at home
  • Exercise break from console
  • Ways to stay engaged (TV)
  • Company fatigue management program
  • Longer periods on the same shift
  • Appropriate staffing levels
  • Eat healthy and drink water
  • Communication between controllers
  • Snacks
  • Focus on work tasks
  • Ergonomic chairs, desks
  • Family support 
  • Naps


Controllers said that the following makes fatigue worse (in order of frequency of response):

  • Schedule issues
  • Not enough rest
  • No snacks caffeine exercise equipment ergonomic workstations
  • Not enough Controllers
  • Not enough time off
  • Family issues 
  • Too much overtime
  • Longer shift rotations
  • No means to stay engaged
  • Not able to take breaks
  • Ineffective shift changes
  • Unhealthy habits
  • Heavy workload or distractions


Alertness is key for controllers to maintain vigilance during monitoring on shift work. In order to maintain alertness, the company needs to make sure that the shift schedule allows for adequate time to rest in between shifts. Providing fatigue management training helps controllers understand key strategies to use on the job and off the job to maintain alertness. The company can also provide healthy snacks and beverages, supportive chairs, sit-to-stand desks, and means to engage controllers, such as TV or Internet, as well as fostering an environment that allows for discussion and assistance with fatigue-related issues. Controllers must also do their part, by getting enough rest, maintaining a healthy diet, drinking water and getting family support. P&GJ 

Authors: Michele Terranova is a principal of Pipeline Performance Group and has over 25 years of experience in human factors and user interface design. Terranova has held previous positions as the director of Human Factors Research at Concord Associates, Inc. and senior research scientist at The Oak Ridge National Laboratory. 

Alicia Gibson is a principal of Pipeline Performance Group and has executive experience in strategy, business development, operations, project management, process improvement and team leadership. She has a background in petroleum, transportation, supply chain, manufacturing, emerging technology and international events management.




77 Control Rooms in U.S., Canada, Australia

62376 Hours




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