The value of real-time decision-making in an oil & gas production process or at a petrochemical plant is closely related to situational awareness. In this setting, real-time is defined as time-critical decisions within seconds based on live real-time data. The control room operator normally operates in a time frame of seconds to minutes, but not all decisions are equally time critical. The reason we specify our understanding of real-time is to make a distinction to real-time that is also used for systems working on real-time data, but offline non-time critical. These kinds of applications are often used more as back-office support for operation and maintenance.
Real-time decisions are important, especially in at least two different scenarios:
- The first scenario covers decisions that the control room operator has to make to mitigate small process deviations. Small deviations may escalate into disturbances with production impact. In a normal operation scenario, the operator leaves the process control to the DCS (Distributed Control System). Once a deviation is noticed, understanding the situation early and performing the correct action brings the process back within its operation envelope with minimal disturbances and losses. If the operator fails to either understand the root cause and to respond or even responds with the wrong mitigating action, the smallest incident may escalate into a major production loss, shutdown or even a hazardous situation.
- Another scenario is after the small incident has led to a shutdown. In this case it is not considered safe to start up production until root causes behind the shutdown are identified.
Situational analysis
How well the control room operator understands the situations is based on a number of cognitive steps:
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Observe and detect deviations
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Find root causes
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Find consequences
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Evaluate against operational targets
It is mandatory to operate within safe operating limits, but optimizing often means being closer to higher limits compared to the safe operating limits. How well the situation is understood is based on different factors, but the most important element is often experience and training.
Decision-making process in real-time
The real-time decision-making required by a control room operator is different in nature to the decision making in the remaining part of the organization. The remaining organization is normally faced with days/months/years. Shorter decision time and potential hazardous impacts is a combination that is challenging to the operators. As a general observation, more attentions should be given towards operators after being through stressful observations. During workshops with operators, we often get a feedback where they want more quality control and learning in job situations. They often ask themselves whether they made the right decisions in the given situations. There are examples of control room operators quitting their job after serious incidents or accidents.
We want operators to have the correct knowledge and experience to make the right, rational decisions based on being aware of the situation at hand and how it might evolve.
The steps to establish a counteraction plan:
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Decide if action is needed
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Select means and methods
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Prepare counteraction plan
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Execute the counteraction plan
How does Human judgement affect the process?
The challenge is following the steps discussed above in a rational way. The human brain is brilliant, but there are also some drawbacks that are not helping us. To be able to follow a rational decision process we spend much more energy compared to the simple process of reaching a conclusion of “I have seen this before, hence I know what to do”. This decision takes milliseconds and works perfectly when stopping a car for a red traffic light, but it does not work in a complex situation (Daniel Kanemann, 2011.)
There are other challenges that influences our decisions. Humans are often not very good at making correct decisions based on statistical information (Kahneman and Tversky, 1974.) The concept of availability, which is probability that an item is operable when it is needed (Uptime/(uptime + downtime) also leads to wrong decisions. In short, the easier it is to recall the consequences of something, the greater we perceive these consequences to be.
real-time decision-support
Real-time decisions in the control room affect the operations with respect to both production and safety. Any decision support needs to be available on-line in real-time to have value. Care must be taken to ensure that the decision support tool can assist the operator in making rational decisions and counter the challenges of human judgement. This will ensure that the plant runs without incidents, which increases safety and production output.
We will not cover all the shortcomings of humans making decisions, but simply state that any decision-support should be designed to counter the effect and shortcomings of human judgement.
