The Human Factor

What Are the Biggest Problems That Control Engineers Face When Going into a Plant?

By Greg McMillan, Stan Weiner

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Warning! This interview was conducted over the course of many beers and much BBQ, leading to an empty head and a full stomach.

Greg: Monsanto started a process control improvement (PCI) program in the early 1990s. A PCI group was funded up-front to find opportunities and implement solutions. Plants did not have to pay for services of the team, but did need to commit to do an opportunity assessment and provide resources based on the benefits found. To benchmark what had been done in the chemical industry, the team visited 12 companies that were considered to be the best in process control. The results were reported to the Chemical Manufacturing Association's (CMA) Process Control Task Group in my June 30, 1993, report, "Opportunities in Process Control."

Stan: The key person in the PCI group who led most of the opportunity assessments was Glenn Mertz, who spent his career in a plant and had skills and a keen interest not only in process control, but also in working with financials. The rest of the PCI group members were modeling and control specialists recovered from what was a world-class engineering technology (ET) department that was doing a disappearing act (another story).

Greg: I visited both Stan and Glenn on my recent vacation in southwest Florida. In talking with them, the importance of the human factor became evident.

Even the best ideas may never see the light of day. Glenn had an advantage going into a plant because he was perceived as a plant person. However well-respected internationally, the corporate PCI specialists were viewed as outsiders. Tribal instincts and egos can get the best of people, particularly those without a technical understanding. The great thing about process and control engineers at the working level is that for them evidence rules. Automation systems are windows into and handles for the process and, thus, the source of evidence.

Stan: What was the biggest problem you faced going into a plant?

Glenn: The statements up-front, "Everything is perfect," or from the less idealistic, "It is as good as it is going to get," were discouraging. The problem was particularly endemic with upper level managers, who wanted to prevent interference with their decision-making process and were more interested in not making past decisions look bad versus making new decisions to look better.

Stan: What type of champion were you looking for at the plant?

Glenn: We succeeded the most when  our key interface had technical understanding, was open to new ideas, looked for the positives rather than negatives, was patient in working through problems, and had a great personal relationship with the operators. I started each day onsite in the control room talking to the operators.

Greg: What other people needed to be involved in the PCI implementation?

Glenn: Absolutely critical was the involvement of the process engineer supporting the production unit and the control engineer responsible for the distributed control system (DCS) configuration. The analyzer specialist and E&I engineers were only needed on an occasional basis since we were doing mostly "quick hits" that simply involved configuration changes.

Stan: What were the most exciting opportunities?

Glenn: We would start drooling when an increase in feed rate was needed. This was the easiest nut to crack and quick to implement.

Greg: The PCI process is outlined in my note pages. "Opportunity Sizing and Assessment." The result of the opportunity-sizing was a gap from the actual versus a target production rate, yield or quality improvement. Simulations were used to establish theoretical targets, but the more convincing target was the practical target found by Glenn by going through the cost sheets. How did you manage to gain access and analyze the cost sheets?

Glenn: Outsiders do not get to see the cost sheets, but from being from a plant and managing my real estate businesses, including doing all the numbers, I could talk my way into seeing and analyzing the financials. I took the best with a grain of salt. The week or month of exceptional performance could be an outlier for any number of reasons.

Greg: It was amazing to me how some plants with many forms of product and many customers had no on-line production rate measurement. Large continuous intermediates plants had recycle stream effects that would build over a course of weeks, confusing process and research for decades. The foremost industry expert in advance process control concluded that model predictive control was a waste of time until a real-time optimization could figure out what is really going on because of the non-self-regulation from recycle.

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