Flow / Safety Instrumented Systems / Systems Integration

No KISS for Digital Integration?

If KISS ("Keep It Simple, Stupid") Is the Tactic to Survive the Combat, What's the Strategy?

By John Rezabek

My son was giving us a tour of his workplace, the "back shop" of Ellsworth Air Force Base, where he and his fellow airmen service the advanced avionics of the B1-Lancer. Along with the 7-foot-tall racks of test equipment for diagnosis and repair of ailing avionics systems, numerous bookcases are filled with volumes detailing the troubleshooting proceedures for each station. This level of troubleshooting and repair is not common though. For many other airframes, this service is performed by civilians back at the contractor's facility.

When systems are intended to steel one's defenses against the most feared adversary, you don't want to scrimp on technology. With superiority hinging on increasingly esoteric technology, there's fear the reasoning/troubleshooting skills, morale and creativity of maintenance personnel may atrophy. But developing cutting-edge top secret technology into serviceable aircraft means using self-diagnostics and expert systems.

One of our basic engineering axioms is: "Keep it simple, stupid" (KISS). It was invented by Lockheed engineers, and was aimed at ensuring that complex, advanced aircraft remained repairable in the throes of combat, far from the sophisticated tools and technical resources available to the designers.

KISS has some applicability in process measurement and control. We are faced with the same predicament: Use the best technology, but don't require engineers to be on call for maintenance. While we're not in an arms race per se with our competition, we are tasked with delivering safety, reliability and quality to our enterprises with diminishing human resources and a smaller budget. If we're anticipating combat-like circumstances during commissioning, start-up, shutdowns and/or midnight callouts, we may be compelled to forego the latest solutions in favor of the tried-and-true. In such cases, KISS may mean just installing 4-20 mA and forgetting about digital integration.

But what if the phone man was dutiful about KISS? He could run copper to our house instead of fiber. That would be fine for my Aunt Edith, but the younger generation might become envious of the neighbors' bandwidth.

Being perpetually resource-strapped and battle-weary may be reality for a lot of us, but is this how we'd choose to practice our profession? If KISS is the tactic to survive the combat, what's the strategy? "No one was ever fired for doing what they did last time"—except maybe André Maginot (look it up). Digital capabilities may never be completely exploited, even by the most talented and motivated end user. Are we scrimping on our duties if we defer to KISS? Where do you draw the line?

Control's editor in chief, Walt Boyes, recently blogged about his visit to a local brewery. When asked about his control systems, the brewer said, "We just want to make beer." This seeming indifference to our specialty is not uncommon, and it hardly inspires one to step out boldly. If the end user is indifferent about instruments, imagine how much they care about networks. But even the little brewery could benefit. For example, if a density measurement came "free" on a Coriolis flowmeter integrated with Modbus, Ethernet or fieldbus, that measurement would be mouse clicks away. So now while "just brewing beer," the brewer can also see when his sparging is complete, boil less water, and save some water and energy.

The capital required for process control is generally small compared to the overall kit, but its impact on long-term safety, reliability, quality and efficiency is disproportionately large. Digital integration of devices and systems may marginally increase complexity, risk and require a new skill set for the service guy, but it's an investment that can be strategic. While "lifecycle cost" and "lifecycle benefit" are practically becoming clichés devoid of meaning, it's a better metric for guiding our specifications than KISS. "Fitness for purpose" should consider all the intelligence and insight a measurement and control system has to offer.