Robots have revolutionized auto manufacturing, making plants safer and products more reliable — and reducing the number of people involved in the process. But walk inside a modern auto plant, and you'll quickly realize that robots have hardly replaced the human touch — at least, not in some areas.
Volvo's car plant in Ridgeville, S.C., which opened last year, provides an object lesson. The facility produces the S60, a luxury sedan, for the U.S. market as well as for export.
The beginning of the production line is highly automated; in the first of three large buildings, robots outnumber human workers 300 to 200. But the end of the process is dominated by people.
Let's start with the robots. Behind a safety fence, a half-dozen robot arms move in coordination as they spot-weld a car body together, whirring softly. The lights in this section of the massive building are dimmed because the robots don't require much light to complete their work.
Robots are indisputably better than humans at some tasks. They're precise and consistent, and they excel at repeating an identical motion over and over again.
Jeff Moore, Volvo's vice president of manufacturing in the Americas, says that in deciding which jobs to assign to a robot, the company starts by focusing on monotonous, physically demanding work — especially anything that carries safety concerns.
"With all the heat and sparks and high current and things like that associated with welding, that's a natural spot to be looking at where you can more heavily automate," he says.
But on other parts of the line, "the human touch has a lot of advantages," Moore says.
Or as Tesla CEO Elon Musk put it last year, "Humans are underrated."
He admitted that Tesla had miscalculated by turning toward heavy automation at its Fremont, Calif., assembly line. After production issues mounted, the electric-car maker reversed course and started giving tasks back to people.
So where, exactly, do humans still beat out robots? Follow the car body down Volvo's assembly line, and eventually the lights become bright as humans attach the hood, trunk, fenders and bumpers.
Then comes quality control. Robots with sensors test the spot welds, and people run their hands over the surface of the metal body, feeling for imperfections. The literal human touch still can't be beat here.
The car body passes through a skybridge to another building, where it gets painted — another task at which robots excel. Then it travels to a third building for final assembly, where thousands of parts from around the world come together to form the finished car. Here, again, humans reign.
People are better than robots at manipulating complex shapes and threading them together — exactly the skills required to attach parts to engines, for example.
These workers also handle different kinds of engines — gas or hybrid, all-wheel drive or front-wheel drive, with or without a turbo and, in the future, even all-electric motors. Humans can switch easily among different tasks and even pick up new ones on the fly; robots not so much.
As Tremaine Smalls attaches drive shafts to engines, with a radio reporter occasionally getting in his way, he shrugs off the complications of working with different engine types.
"It's kind of the same process, just different drive shafts," he says, showing how he checks part numbers against a piece of paper to confirm that each engine is being set up correctly.
Jason Dodgins, working on the same line, used to be a team leader for a bearing manufacturer. There, he says, his job was to run a computer-controlled machine.
"The machine did a lot of the actual labor part," he says. "You were basically doing the inspection." Working on this auto assembly line, in contrast, "has a lot more manual labor to it," he says.
As the engine moves along the line, humans and machines divide the work. Kayla James, just two weeks into this job, uses a mechanical lift to install an exhaust system; it takes away the physical strain of the task. Later, a large machine installs dozens of bolts simultaneously — but between each cacophonous volley, Brandon Marshall loads the various bolts into place.
Humans edge out robots at these tasks even when everything is going smoothly, but they have a particular advantage whenever things go wrong.
In modern auto plants — inspired by the revolutionary production philosophy of Toyota — workers are encouraged to stop the line whenever there's any kind of a problem, big or small. (At plants like this Volvo facility, workers pull a cord and music plays — a different song for each location signals where an issue has come up.)
Robots, too, can identify certain mistakes coming down the line, but humans have a distinct advantage when it comes to solving those problems.
Consider Volvo's radiators. At one key point in the line, the car body — waiting in an elevated conveyor — descends on top of the engine, transmission, axles and everything else that makes the car actually move. They come together at the "marriage point."
"If this radiator is not pushed back far enough, it will crash with the body," says Trey Yonce, who helped set up the marriage-point line.
The original production process called for rubber bands to hold the radiator in place for that key moment, but a laser sensor would frequently detect that the radiator wasn't in exactly the right spot. Machines could flag the problem to be fixed.
But humans, unlike robots, get annoyed by repeated problems.
"They just got tired of doing it, and a fellow came up with an idea and it worked," Yonce says. He points to a little yellow piece of plastic, more effectively holding the radiator in place — an improvement to the process.
Moore, the Volvo vice president, says the company has already applied for multiple patents based on ideas that came from workers at this new plant.
Humans have strengths, compared with robots, in all sorts of workplaces — not just auto plants.
And in general, people and robots work best together, with robots handling dangerous, monotonous jobs and precision work, while people handle tactile work, switch between tasks, make decisions — and come up with creative ideas for improving things.
There's a philosophical lesson here, in a way.
"People often think of manufacturing workers as actually a poor substitute for a robot," says Susan Helper, an economist at Case Western Reserve University. Like a machine that complains, gets tired and makes mistakes.
And historically, some factories have tried to treat their workers like robots, separating "brain" work from "hand" work and pushing assembly line workers to do repetitive tasks without thinking. In this setup, a robot is an upgrade from a human worker: It won't complain or get tired.
"But in practice, these things are really difficult, and the assembly line worker is making judgments a lot," Helper says. "And it turns out that when you take that person away, you end up with some problems that are hard to solve."
That means the best thing robots can do for manufacturing is not replace people — but free them up to work like, well, people.
RACHEL MARTIN, HOST:
Robots have revolutionized auto manufacturing, but they've hardly replaced the human touch. NPR's Camila Domonoske reports.
CAMILA DOMONOSKE, BYLINE: At Volvo's new plant in Ridgeville, S.C., a half dozen robot arms move in coordination behind a safety fence. They're spot welding a car's body together. Eventually, this will be an S60 - a luxury sedan.
(SOUNDBITE OF MACHINE WHIRRING)
DOMONOSKE: A small cluster of sparks flies up. We are at the very start of the production line...
(SOUNDBITE OF GEARS GRINDING)
DOMONOSKE: ...Where metal components are combined to form the car's body. Here, automation dominates. There are more robots than people in this building. And right here, where the robots are welding roofs together, it's dimly lit. Robots don't need much light to work. Jeff Moore is the head of manufacturing for Volvo in America. He says when you're thinking about what jobs to assign to a robot, you start with work that's repetitive, especially if there are safety concerns.
JEFF MOORE: With all the heat and sparks and the high current and things like that associated with welding, that's a natural spot to be looking at where you can more heavily automate.
DOMONOSKE: But follow the car body as it moves down the assembly line and soon enough, the lights come up and humans take over. At the other end of this building, people run their hands over the surface of the metal, feeling for imperfections. There are some things robots are better at than people. They're precise and consistent. But there are other things people are better at. Humans are underrated, Tesla CEO Elon Musk tweeted last year after Tesla tried to switch to an extremely automated system. Ultimately, the company gave jobs back to people.
And we're good at more than just testing how things look and feel. Here at the Volvo plant in another vast building, a long line of people are preparing engines to go inside the cars. This work involves a lot of fiddly parts with odd shapes, which need to be threaded together or moved around in complex ways. Robots are bad at these fine motor skills. People are great at it.
And this line handles different engines - gas or hybrid, all-wheel drive, eventually electric motors. They all take different parts. Humans are good at switching back and forth. Robots - not so much. Jason Dodgins, working on this line, used to work at a plant that made bearings. That was less hands-on, he says.
JASON DODGINS: The machine did a lot of the actual labor part. You were basically doing the inspection. This has a lot more manual labor to it.
DOMONOSKE: Then there's problem-solving. Skip ahead down the line and workers have put together the engine, transmission, axles - everything to make the car go. The car body is waiting on an elevated conveyor. Now the two need to come together. Trey Yonce helps set up the line where this marriage happens.
TREY YONCE: If this radiator is not pushed back far enough, it will crash with the body.
DOMONOSKE: At first, workers had to fix the placement again and again. Now, a robot could see that problem, but it won't get annoyed by it. People?
YONCE: They just got tired of doing it. And a fellow just came up with an idea, and it worked.
DOMONOSKE: He points to a little yellow piece of plastic. It holds the radiator in place to prevent that crash. Jeff Moore says Volvo has already applied for multiple patents based on ideas that came from workers at this new plant.
(SOUNDBITE OF MACHINERY)
DOMONOSKE: Humans have strengths compared to robots in all sorts of workplaces, not just auto plants. And in general, people and robots work best together, with robots handling dangerous, monotonous jobs and precision work while people switch between tasks and make decisions. And there's a sort of philosophical lesson here. Susan Helper is an economist at Case Western Reserve University.
SUSAN HELPER: People often think of manufacturing workers as actually a poor substitute for a robot.
DOMONOSKE: People complain. They get tired.
HELPER: So, gee, wouldn't robots be better?
DOMONOSKE: That's a fundamental misunderstanding, she says.
HELPER: But in practice, these things are really difficult. And the assembly line worker is making judgments a lot. And it turns out that when you take that person away, you end up with some problems that are hard to solve.
DOMONOSKE: Historically, Helper says, some factories have tried to treat their workers like robots - doing repetitive work without thinking. The best thing robots can do is not replace people but free them up to work like people. Camila Domonoske, NPR News, Ridgeville, S.C.
(SOUNDBITE OF EMERALDS' "GENETIC") Transcript provided by NPR, Copyright NPR.