How I Learned the Most Valuable Lesson About Process Control

A long time ago - when I was a 20‑year‑old Materials Engineering undergrad on a country road in rural Pennsylvania - I learned the most important lesson of my process‑engineering life. I was working at Pittsburgh Corning’s glass block factory, home of those unmistakably 1970s basement‑window blocks. I had zero real engineering experience, just enthusiasm and the belief I could change the world.

Glass Science is the youngest of the material sciences. Metallurgy degrees date back to 1765 at TU Bergakademie Freiberg; Glass Science didn’t become a university discipline until 1915 at Sheffield, followed by Alfred University in 1932 - my alma mater and still the only U.S. university awarding a PhD in Glass Science.

So when I arrived, glass processing was still halfway between alchemy and science. Rick, my boss, walked me through Line 1, a 300‑yard haze of smoke, mold‑release overspray, and heat blasting from the tank of molten glass. The first 20 feet were everything: molding. The rest was just cooling, sealing, and annealing.

Rick showed me the defects, cracks, belt marks, and especially chill rings, which are concentric rings caused by uneven flow as the gob cooled. On these heavy blocks, chill rings drove scrap to nearly 40%. “This is where heroes are made,” he said.

My Assignment

Reduce chill‑ring scrap.

He handed me:

• A glass‑processing article

• A digital scale with a data port

• LabVIEW

• A book on Statistical Process Control

The article made one thing clear: gob weight was the critical process parameter.

While learning LabVIEW and SPC, I started baselining the process. Even before I knew the word gemba, I knew the mold‑press operators held the real knowledge. And since you could smoke on the production floor, I sat with them, smoked, and listened.

The operators were unforgettable:

• Jack (A Shift): senior, serious, considered himself an artist.

• Mike (B Shift): young, passionate, convinced he was better than Jack.

• Spot (C Shift): the plant bookie; not the most serious character.

• Vic (D Shift): fresh off his fourth rehab stint, usually asleep / passed out on the bench - earning him the nickname “Drunk Vic.”

After two months of data, a pattern emerged: Drunk Vic had half the scrap rate of everyone else. Rick told me to recheck. I did. Same result.

So I deployed my scale system - pull a block, weigh it, log it. After a few weeks, the control chart told the story: gob weight went out of control at every shift change - except Vic’s.

Back to the Gemba

Shift‑change observations revealed the truth:

• Jack: tidy, “fix” everything

• Mike: adjust to “improve” Jack’s setup

• Spot: quick tweaks, then off to take bets

• Vic: sit, grunt, pass out

The physics were simple: massive heat, massive mass, massive inertia. Left alone, the process stayed stable and changes slowly. The operators’ compulsive need to “fix” things created the variability.

Vic inherited stability and did nothing. Therefore, Vic was the best operator.

I tried explaining the science. I got:

• “I was running this press when you were a twinkle in your dad’s eye.”

• “This is an art.”

• “You can’t tell me how to do my job.”

I had the answer, but I couldn’t change behavior.

So Rick and I built a “control panel” with switches and buttons. We told the operators it would help them run the machine their way. They loved it.

I asked one thing: “If the chart shifts up, turn that bar one click left. If it shifts down, one click right. It’s for my semester project.”

The Payoff

The bar controlled gob weight. The panel wasn’t connected to anything. With the operators no longer over‑adjusting, scrap dropped by half within weeks.

Rick was right. I became the process hero.

What Drunk Vic Taught Me

·       Processes run best when you set them up correctly and then leave them alone.

·       Adjustments should be predetermined and data‑based.

·       Human instinct to “fix” things is no match for physics.

Thanks, Drunk Vic!