The key hole effect: Your control room operator is monitoring a process with several loops and several points, they have multiple screens and each screen has hundreds of graphics to navigate through, uh oh, several alarms start to activate! The operator begins to navigate through several graphics to determine the problem but has a very limited view because there are so many screens to click through. We are operating outside the operating limits, and this is about to get ugly. The operator is on the tail end of a 12 hour shift, 10 screens are flashing all at once, he’s trying to figure out what is happening, he is struggling. The supervisor is out in the field. The radios are down and the clock is ticking!
The image above is a real example of the number of screens that were selected after a few alarms activated where the operator navigated for several minutes trying to determine the situation. During this time, the process was outside the desired operating limits. This has several negative effects on equipment, quality, and raises safety concerns.
Data Overload or the Key Hole Effect in control rooms is costing companies millions of dollars per year. Control room operators rely on alarms to alert them of a problem. (reactive instead of proactive) Why? They do this because they have a ton of information to process, they have several graphics cluttered with data that requires mental calculations to process the information. Most operators do not have a good way to identify where problems originate and what to do, so they rely on alarms. Hey, you might get lucky and have an operator on the right screen at the right time, but it does not mean he is going to see that increase in temperature amongst all the other data on the screen.
When operators rely on alarms and several activate during a problem, operators react and start to investigate. Ideally we want the operators to detect problems or see them coming and prevent the alarms from activating. The idea is to encourage operators to maintain the process in a steady state, detect abnormal situations, and act accordingly. Unfortunately most operators have to rely on alarms before they even know what is going on. Problem: If operators wait for alarms before they act, it will extend the amount of time they are operating outside the operating limits.
Why does it matter? When we are in alarm, we are in “abnormal mode”, we are outside the desired safe operating limits. If we are operating outside the operating limits the process may be unstable and creeping up to a potential incident. Alarms are set to protect assets, equipment, people, quality, and reduce waste. If an operator gets 100 alarms during a shift and each alarm is “in alarm” an average of 3 minutes each, that means that you have been operating outside the operating limits for five hours. Is that okay? It shouldn’t be, that’s why we have alarms and operators, they are extremely important!
We often worry about how many alarms we get during a shift but we also need to focus on the amount of time that we are “in alarm”.
Alarm: A problem that requires action! We have operators in place to intervene and return things back to normal, they do this through observation, procedures, experience, training, and communication. Unfortunately we keep seeing issues with the operators environment, user interfaces, and management systems. These issues prolong “time in alarm” and make it difficult for operators to solve problems.
We want operators to detect problems, prevent alarms, maintain a stable process, and react as quickly as possible. Remember, while you are operating in alarm you are operating outside the safe operating limits…are you measuring this at your site and have you determined what the negative effects are?
Companies spend millions of dollars on asset management. One of the biggest missed opportunities is likely the biggest asset “the people”. Companies spend millions of dollars staffing, training, and filling important positions like process operators but they don’t spend the time to design the user interface to support the objective – to operate within the desired, safe, set boundaries of the operating limits.
Many managers believe they have spent a ton of money to design the graphics they currently have. In most cases, the DCS vendor and engineers simply copied P&ID’s and never spent money on user centered design, specifically human factors design.
The graphics need to be designed with a human factors expert that understands the process, the console operator is key, and the process engineer. This team of 3 is critical to the success of the design. We have to bring the big picture back, we have to use analog objects that reduce the need for mental calculation and trends that provide in depth situation awareness. The information needed on the screens must be based on a thorough task analysis. Until we get this right, operators will operate outside the operating limits and companies will continue to lose money and safety will be jeopordized.
I talk to several engineers every day, I always hear the same things, we are doing some things to address these issues but we could do better. We do not have money in the budget for this but it’s a good idea. Upper management does not understand this.
Solution: Arrange a presentation at your site and make sure upper management is there.
Many of our clients have started out with an operator staffing / workload assessment, to determine how many operators they need and how to best balance the workload between them. This assessment will score each position and calculate the total workload. At the same time it will identify gaps in the environment, interfaces, and management systems, identifying what is contributing to the workload, so you see how you compare to best practices, how you can reduce operator workload, improve situation awareness, enhance operator performance, prevent alarms, and reduce time in alarm.
We spend a lot of time trying to optimize the process – now we need to optimize the operators by providing them with the tools, environment, and interfaces they need.
“Operators are the pilots of the process – So we give them wings”
UCDS is a Control Room Human Factors Company with 100 years of combined expertise in control room operations. Our design services help operators detect, diagnose, and respond to abnormal situations so they can prevent major incidents, recover quickly, and operate within the desired, safe, set boundaries of the operating limits. www.mycontrolroom.com
Stephen Maddox, Sales Director, 512 868 6798 firstname.lastname@example.org