Fred needed a new vehicle to pull a heavy trailer. He found a new SUV brimming with clever features, including some that were purported to help with towing and trailer backup—something he really needed. But after a year of ownership and numerous trailer towing episodes, he was still struggling to utilize the unfamiliar tech effectively.
Fred could see his surroundings and his vehicle from numerous angles, including a view depicting the SUV from above. But when backing up the trailer, he still stuck his head out of the window, occasionally getting a few shouted suggestions from his spouse.
There are instances where a control professional’s cleverness and creativity can impact usability in a similar way, as Fred discovered when he proposed using a valve position control scheme. He was uncertain about the capabilities of a positioner for a large butterfly valve to operate the valve with enough resolution, accuracy and repeatability, amid concerns about hysteresis and deadband. His scheme aimed to improve the precision of a pressure control scheme that utilized the coarse (large) valve to keep a smaller valve in its optimal control range.
It's especially concerning during uncommon transitions in the process operating state—startups, shutdowns, significant rate changes, or changes in product slate or specification. This doesn’t happen every day, just as Fred wasn’t backing up his trailer daily, not even every weekend. What should one do with setpoints and modes when, suddenly, a downstream unit has a steam outage, and rates must be reduced immediately? Breaking out procedures or training literature at such junctures is akin to Fred reading the manual while blocking traffic, amid horns honking and profanity, as he tries to maneuver his trailer.
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Giving operators guidance about what the automation system is doing can be useful, but unfamiliar changes—one individual memorably struggled to move a valve, while the faceplate was flashing “check target mode”–aren’t guaranteed to register in the operator’s mind, especially under duress. Onstream help may only prove effective when there’s ample time for deliberation and discussion and checking understanding with those who are more experienced. What will the novice do when the veteran isn’t there to give advice and orders, and the flare’s plume of fire and black soot ensures his manager will be interviewed on the evening news?
Control professionals like Fred increase their odds of success when their control schemes remain operator- and novice-friendly. In some cultures, our peers see themselves as providers of “infrastructure," but when one seeks to fully exploit the computational power and capabilities of modern control systems, it’s important to engage with the real end user—the board operator. More complex schemes that are in service routinely can be building blocks for easing acceptance and understanding of other advanced control applications.
One might make some effort to depict these schemes graphically, revealing what’s under the hood, possibly using custom subpictures or popups that reveal the details in real-time. Those with the time and resources to use a process simulator or a useful digital twin are especially fortunate, and such platforms coupled with regular drills or challenges will improve understanding, as well as suggest improvements for the systems engineer.
While Fred’s trailer struggles may cause a kerfuffle at the campground, underutilized or disabled control schemes can impact the enterprise. Advanced controls improve profitability, reliability and safety, and impact on the environment. Our end-user board operators need to be confident and comfortable to ensure they’re fully utilized—so we don’t find they’ve backed up into manual control.
