"Most of this work was done at Wright Patterson AFB and Wright State University, both in Ohio, and this is also how the field of human factors came about," says Dave Strobhar, PE, chief human factors engineer at the four-year-old Center for Operator Performance (COP, www.operatorperformance.org), which also is located at the university. "As the interest in operator performance issues such as alarms, HMIs, training and teams has grown, voids have been found in the available information. People estimate how many alarms they think operators can handle based on other industries, but most of these numbers are pretty arbitrary."
COP's members include BP, Chevron, Marathon Oil, Flint Hills Resources, Nova Chemical and Suncor Energy, as well as Emerson Process Management, ABB and is managed by Beville Engineering Inc. (www.beville.com). Though the center is relatively new, Strobhar reports its members' experience is extensive. In fact, in the past 25 years, Beville has performed 125 alarm rationalization projects for clients about how to respond to alarms, and reports that it can reduce alarms in most applications by 50%-75%.
"What we need is a free flow of information, so we can find out the best way to present data to operators and have academically defendable research about how to do it," says Strobhar. "We're also tackling topics like simulators, so when users are trying to decide between high- or low-fidelity simulators, they'll know the incremental performance benefits they can get based on how much more they're spending."
To help users understand situation awareness and adopt user-centered design, ASM Consortium has made many of its recommendations and documents available to a wider audience. Peggy Hewitt, ASM Consortium's director and Honeywell's marketing director, reports that users can even order them at Amazon.com. "We have 15 years of research on best practices and the real science behind user-centered design principles," says Hewitt. "We have experience applying user-centered design when our customers apply our products, but we also consider it a core product development process."
Strobhar adds that COP has done several pilot studies on situation awareness and user-centered design issues, and found in its "Expertise of Process Control Operations" study that training and practicing decision-making skills can greatly help operators. Likewise, another study in 2007 showed that military-style decision-making exercises (DMEs) can be applied to process control settings, and some of these methods reportedly have been adopted by Flint Hills Resources.
Strobhar adds that COP also is working with Louisiana State University to study human response to simulated alarm rates, and is finding that the traditional view of performance degrading at one alarm per minute may be too conservative, and that two alarms per minute may be closer to where response begins to lag. Using these findings, they're also learning that better methods of presenting information to operators can improve their performance. "Traditionally, alarms are presented chronologically, and most operators still prefer it, but this is only better when alarms come in at a slow rate. When alarms are coming in quickly, we're finding that grouping alarms by priority allows operators to react and solve problems 40% faster. As a result, we're also going to study the best ways to switch between these two chronological and priority-group formats."
Finally, after learning that shapes and colors in displays aren't as important as data content, Strobhar adds that COP is also examining how "cluster analysis" and more thoughtful and subtle color use can help present on-screen information so it makes more sense to operators. (Figure 2) "Critical information is often located on multiple screens, which requires users to scroll a lot, move from page to page, and remember earlier numbers too much, so we're study how to create a method to better organize this kind of information."
Though aircraft builders and military planners are further ahead on situation awareness, Nimmo agrees that process control developers are beginning to catch up. In fact, Nimmo adds that UCDS' three-day workshop can show users how to deploy better-performing graphics that can improve operators' process detection and diagnostics by 30%, and reduce response time by 50% in many applications.
Navigation, Procedures and Commitment
Similarly, Honeywell and the ASM Consortium have applied user-centered design in the areas of effective operator displays and alarm management for more than 10 years. Hewitt reports that the same principles are also being applied to how companies develop procedures in their organizations. "We've done a lot of research in the past couple of years on procedural operations, and trying to understand how console-based and field-based operators need to interact with their procedures," says Hewitt. "A lot of user-centered design is giving operators information when they need it." (Figure 3)