The COP has just released the preliminary results from a project called “How Many Alarms can an Operator Really Handle?” being carried out at Louisiana State University, Baton Rouge, La. Here, a pipeline simulator was used to try to understand the overall number of alarms that operators are capable of dealing with and how their responses are affected by display format.
“Up to now, the number has really been based on a best guess. But, of course, the regulatory bodies look at the number and use it as if it is based on lots of research. So, we are looking at whether this number makes sense,” says David Strobhar, principal human factors engineer at Beville and a founder of the COP.
Fifty students contended with five different alarm actuation rates via two alarm display formats. Response time, acknowledgement time and the accuracy of the response were among the metrics tracked. The students performed about equally for the four lowest rates, and the same with either display format. However, the highest rate prompted a significant (60%) decrease with one display format, but not as much with the other.
This raises important issues concerning information presentation and training, says Stobhar. “For example, if you train people in different alarm-management techniques, will they be able to handle them? If the alarm rate goes above a certain level, you might need two operators on a console — at an increased cost of about $500,000/yr. But could changing displays and better operator training achieve this? So, overall we are beginning to objectively understand operator performance with alarms and how it is influenced by presentation — and helping to identify the best allocation of funds.”
The COP also now is comparing the responses of the students with those of trained operators to see, for example, if the alarm rate problem occurs at the same point. The final results are due to be presented at its spring meeting at Wright State University in Dayton, Ohio.
Another COP initiative is to adapt exercises that the U.S. Army uses to train battlefield commanders for decision-making under stress and apply them to process plants and pipelines — for low-cost drills to improve decision-making and build expertise. A handbook and video on how to develop different scenarios is already available to the organization’s members and one, Flint Hills Resources, Wichita, Kan., is rolling them out to trainers at all its refineries in the first half of 2009.
“In terms of feedback, those involved in this training exercise have raved at its power and simplicity,” notes Strobhar.
The center also wants to develop a better understanding of what information operators actually use compared with what information they should be using. This would build upon an expertise study it already has carried out. Operators of a crude unit were tested on 13 levels of expertise against operators of a catalytic cracker at the same site. “The operators on the crude unit scored higher, which was a surprise to the company as they felt the best operators were on the cat cracker,” says Stobhar.
Further investigations revealed that the catalytic cracker had been on advanced control for a decade, while the crude unit had not. “Advanced control had degraded the skills of the operators on the cat cracker. They ran it on auto-pilot. So there was a difference in the level of expertise and the challenge is how to get this back. How often should retraining be given, for example? This is the sort of thing that we want to quantify,” he adds.
The COP also wants to study simulators and displays, including use of color and grey backgrounds. “More importantly, the need to understand what data is being used to make decisions has been identified and will likely be one of the next projects. Finally, a survey of simulator research and use revealed problems in the industry’s fixation with fidelity. One of the identified needs was to have a common metric of fidelity to provide a basis for comparison and discussions,” concludes Strobhar.