2021 Control Process Automation Hall of Fame: John Rezabek

When John Rezabek graduated high school in the 1970s, the long and fruitful career in process controls and instrumentation that was to come wasn’t yet on the radar. Rather, he enrolled in the Cleveland Institute of Music with ambitions of playing trombone for a symphony orchestra. “Being the young, idealistic person I was,” Rezabek says with a wink, “I thought I could play my trombone and inspire the nations to live in peace.”

But a funny thing happened on the way to the philharmonic. He had a side gig doing arrangements and playing in the brass section of a lounge band that headlined at exotic venues like the local Holiday Inn on weekends. “I had an awakening,” Rezabek says. “Somewhere along the line I came to the realization that to thrive in this society, you have to do something that people truly value. But I did learn that it was good to be part of a team, and to be contributing in a meaningful way.”

Rezabek carried that life lesson forward, as he completed his B.S. in systems engineering at Case Institute of Technology, and then joined Standard Oil of Ohio’s corporate engineering group in 1981. As occurred at many of the oil and gas majors during the 1980s, personnel cuts at corporate led Rezabek to take a position as an analyzer supervisor at the company’s Lima Refinery. So began a series of process control assignments that had Rezabek working for four different legal entities—BP Amoco, BP, International Specialty Products, and finally Ashland—without technically changing organizations.

Through the years, his work with analyzers in particular “opened the thought of digital integration—it’s a term I’ve used forever,” he says. “If you have a microprocessor-based device, and a microprocessor-based host, they should be able to talk together.” Back then, analyzers were more prone to go off in the weeds—due to sample system issues or other causes—and you just didn’t know it, Rezabek says. This hampered the ability of operations folks to trust the analytical measurement, especially for closed-loop control applications. “It was ‘I think I’m going to shut that off and run it in manual because I don’t know if the analyzer is working correctly or not.’

“But with digital integration—using Modbus at the time—you had data validation, plus diagnostics,” Rezabek adds. “You could get a clue from afar if something wasn’t right, whether the measurement was okay or if something needed to happen.”

Rezabek’s second encounter with the power of digital integration came when, during a major modernization, the plant had the opportunity to use Honeywell smart transmitters that spoke digitally to the Honeywell DCS. “It was a great advantage. The DCS could bring in case temperature from all the instruments, and the operator could tell if an instrument was freezing up or getting too hot. “One of the operations team leaders attributed that insight to keeping the refinery running through the winter. That really stuck with me, and I thought we should have it all the time.”

Then the opportunity came to be at the vanguard of digital integration: a new BP chemical plant was on the drawing board just as FOUNDATION fieldbus was being readied for market. “It was a compelling pitch, and served the vision of digital integration,” he says. From there, Rezabek admits he became “a bit of an advocate” for fieldbus, including a stint as chair of the Fieldbus Foundation’s end user advisory group. In that same period, he became a regular columnist with Control, and has now shared his perspectives on digital integration—and other related topics—for 15 years and counting.

When asked what words of wisdom he would impart to those just starting out in a process automation career, Rezabek counsels to not forget who the real end user is. “It’s often missed that we in engineering are service providers to the operations organization. They’re making the product that pays the bills. Seek their input and aim to make them more effective. It helped me be a better engineer—and get the systems I designed used and maintained.”

Some things haven’t changed since Rezabek’s days as a contributor to the success of that lounge band all those years ago. “The feeling of being accepted as a trusted member of the team is tremendously satisfying,” he adds. “When I walk into the control room, I get, 'Oh good, John’s here.' That’s what keeps me working.”

In short, “Hope that they welcome you when you come, and hate to see you go.”