By Gill Grady
People tend to do things that make sense to them at the time to achieve their goals. But the question is why did it make sense for them in that moment? 
To understand the concept, let’s follow Hector, a relatively new console operator. His supervisor stepped out of the control room unexpectedly, and of course that’s when an alarm goes off. Hector’s heart rate and blood pressure rise, beads of sweat appear on his forehead, and his view narrows as tunnel vision begins. Did he miss an important trend? Is the low flow alarm due to an unexpected valve closing, a pump failing, or even a hazardous leak that may require him to alert emergency personnel and shut down the process?
How Hector handles this situation depends upon two critical skills. The first is his recognition skill to select the appropriate cues from the information being presented and form a mental model of the situation at hand. Second is his cognitive skill to forecast what is about to happen, assess if there is sufficient time, and take the necessary steps to recovery. In other words, his situational awareness.
Dr. Mica Ensley famously identified three levels that define situation awareness as:
- Perception of data and the elements of the environment (Level 1)
- Comprehension of the meaning and significance of the situation (Level 2)
- Projection of future states and events (Level 3)
Situational Awareness (SA) is also impacted by a variety of environmental factors such as workload, culture, stressors, and system design, as well as individual factors such as preconceptions, knowledge, and training. So, how can we use simulation to improve situational awareness in the process industry?
Researchers  have applied Ensley’s model to the process industry to identify common causes of error at each level. GSE has gone one step further by identifying how EnVision tutorials and simulation models can build the skills needed to minimize those errors in operators and teams.
Here is a small sampling of how you can use your simulator to train operators to avoid the various error types. A full list, Situational Awareness Error Taxonomy is available upon request.
Level 1: Failure to directly perceive information
Data not available: Data is not available due to failure of the system design to present it, or failure in the Distributed Control System (DCS) or other communication and control systems. Inserting malfunctions such as transmitter drift or a valve failing open/closed can present faulty information to the operator. This forces the trainee to evaluate all information presented to notice and understand the true current state of the process.
Misperception of data: Data is misperceived due to influence of prior expectations or misunderstood due to task distraction. Faulty information or actions (e.g. lining up the wrong pump or process line by instructors acting as outside/field operator) can test the console operator’s ability to verify actual plant status. The ability to fail a piece of equipment in multiple ways, such as pump degradation vs failure vs seal failures can test whether the operator is misperceiving data based upon past experience. Even with oft-practiced failures, a different timing or severity can be used to generate a response different from the expected. With the instructor involved we can also introduce the necessity of closed-loop-communication between people and make intentional mistakes. An interesting excise is to have to Trainer (Field Operator) reply on the communication with the phrase OK and then misinterpret the message. How does a Control room operator notice the fault and how do they act? SA is also about sharing your mental model with others to see if you are still on the same page.
Level 2 Failure to correctly integrate or comprehend information
Lack of or poor mental model: A poor mental model does not allow for combining information needed to meet goals. Primarily associated with automated systems. Automation can act as a barrier to really understanding what is happening in the system. EnVision tutorials provide the necessary background information used to understand the process and a structured way of information gathering (monitoring) combined with evidence-conclusion relationship comprehension. Our critical thinking exercises ask the operator to anticipate the results of a change in state, perform the operation and document results. Immediate feedback helps the student correct or confirm their mental model of plant performance.
Level 3 Failure to project future action or state of the system
Lack of or poor mental model: Information of current state is correctly understood, but projection of that state into the near future fails because of poor understanding of how to do so. Multiple step change exercises and startup practice allow the trainee to test and develop understanding of cause/effect and the timing of transients. Improving their (meta) cognitive skills by constantly developing, testing, evaluating the “story.”
Executing habitual schema: Performing task automatically can result in important system cues being overlooked. Introducing small malfunctions during repetitive and routine procedures can test operator’s observation skills. Best practices of scanning trend graphs for anomalies can be promoted, where the trainee needs to self-discover the way to execute these actions. In general simulations are built and used without PLC logic or similar automated operations. Trainees therefore develop their own diagnostic, critical thinking, and operating skills.
Of course, this is just a small sampling of how the EnVision simulator can be used to train operators to avoid the various error types. Download our full list titled Situational Awareness Error Taxonomy.
Situational Awareness is also affected by the operator’s cognitive workload, which impacts decisions and actions. Simulators have often been used to enable operators to practice routine maneuvers of the process, building familiarity that reduces the mental workload. For new operators, like Hector in our example, nothing is natural, and capacity is spent in both understanding and validating that understanding. This adds to the cognitive workload during abnormal events.
Using simulator time enables operators to self-discover relevant cues. This has a greater impact on their recognition skills when compared to identifying important cues in a situation. The operator builds confidence, which enables him or her to properly monitor and interpret information being presented during normal and abnormal operations or emergency events.
For practiced-based training, feedback on results as well as on performance is vital in order to correct the operator’s mental model and to infer objectives for improvement. To help accomplish this in an autonomous fashion, GSE created critical thinking exercises which improve and test the students understanding of cause and effect, help build the proper mental model, ensure their observation skills are honed and provide immediate feedback to correct any misunderstanding.
The EnVision simulator can also be used to address other error types including:
- Data hard to discriminate or detect
- Failure to monitor or observe data
- Misperception of data
- Memory loss
- Use of incorrect mental model
- Over-reliance on default values
- Over-projection of current trends
- Failure to maintain multiple goals
To learn more, contact us today.
 Paull Gantt, Ron Gantt – Safety Compliance Management Inc.
 Mohsen Madeerpour, Salaman Nazir and Jie Lu – The Role of Situation Awareness in Accidents of Large-scale technological Systems.