Heidenheim, Germany. To position itself in China’s rapidly expanding high-speed rail sector, Germany’s Voith Turbo has built what it says is the world’s most flexible factory and has been driving development of pioneering technologies for gear manufacturing.
Wolfgang Hütter searches through the papers in the factory cabinet, finally locating the meter-long rolls where the machines are documented. Usage rates, setup times and hourly costs are all carefully recorded, as are the flow of materials and operators’ working hours.
The World’s Most Flexible Factory
Three years ago, Hütter was commissioned to create the world’s most flexible factory. The task would demand some serious focus. “This was the first time we’d done any real factual groundwork,” the 50-year-old veteran recalls. “Previously we just had an intuition as to how things really worked.”
Hütter has traveled a long career path — from apprentice to programmer to manager with responsibility for tool technology to highly driven innovator. Working days at the factory and studying business administration at night, he was inspired by Toyota’s lean manufacturing and Henry Ford’s “one-piece flow” system, where a worker manages a succession of tasks, following the workpiece from machine to machine.
Powering Voith Power
Voith is a family-owned engineering group with 40,000 employees and revenues of $7.4 billion. Every second sheet of paper in the world is produced by a Voith Paper machine, and a quarter of the world’s hydro-electric power is generated using its turbines and generators. Other activities include the manufacturing of diesel engines and train couplings, as well as innovative transmission solutions for the rapidly growing wind power market.
Gears and transmission equipment make up one of the group’s strategic product areas. Before the new factory, everything was manufactured in a single plant — from enormous gears for ships, mining equipment and wind turbines to small bevel gears for the automotive industry.
Some expensive large machines had such low usage rates that management considered them too inefficient for the highly competitive Chinese market.
China Investing in High Speed Trains
According to the World Bank, China’s investment in high-speed trains is the largest railway investment in history. The first route — a 75-mile stretch between Beijing and Tianjin — opened in August 2008, and today the superfast trains hurtle along the route at speeds in excess of 185 miles per hour.
Ten additional high-speed tracks have since been added, covering more than 4,000 miles. When the stretch between Beijing and Shanghai opens in 2012 (an investment of $40 billion), the total will be more than 8,000 miles. China will also add some 12,000 miles to its conventional rail routes during the same period; which will then span approximately 68,000 miles.
To keep pace with these developments, Voith Turbo decided to build a new factory in Mergelstetten, Germany. Hütter was appointed project manager and given the freedom to come up with some radical new thinking.
He quickly realized that it should be a continuous flow plant, where the expensive key machines would control the pace and where even very small volumes — down to just a single transmission — would still be profitable. One requirement was the use of 5-axis lathe-milling machines instead of the expensive special machines typically used in the gear industry.
The breakthrough came when Voith Turbo began a strategic partnership with equipment manufacturer Heller in Nürthingen, in southern Germany, and developed tools and machining strategies for the technology is now patented by Voith and Heller.
“Sandvik Coromant was there from the beginning,” Hütter says, “contributing customized tools, but also optimization suggestions and ideas about machinery and production strategies.”
Milling with Sandvik Coromant
Kenneth Sundberg, based in Düsseldorf, Germany, is responsible for the global commitment to gear milling at Sandvik Coromant. Although the company is a newcomer to the technically challenging gear industry, he is optimistic. “in 2009 we made a strategic decision to focus on gears,” he says. “We are now investing heavily in technological development and competence building. Our goal is to be perceived as the technology leader for the global gear industry by 2015.”
Michael Skarka, 34, is an operator at Mergelstetten, working on a Heller MCH-350-C milling machine equipped with Sandvik Coromant tools. Behind the glass screen the machine is busy working the raw material — grinding edges, cutting out the tooth gaps, and grinding gear shafts. The process used to take 5.5 hours, he says. Now it’s down to 2.5 hours. Skarka adds that he enjoys working at the forefront of technology development.
Hütter marches briskly through the plant, checking on the flow. “No one else works this flexibly and efficiently,” he says with obvious pride. “This is my baby, and I find it hard to stay away, even in my free time!”
The results have been beyond expectations. A train transmission used to take six months from
order to delivery. Today it takes just two months. The 160,000-square-foot factory is equipped with 16 cranes, making it easy to move machines and quickly change the entire production layout. A three-foot-thick concrete floor throughout the plant allows machinery to be grouped in any constellation.
Forty different transmissions are produced over the three-shift production schedule.
Following a major investment in education — more than 400 different courses, some lasting as long as six months — the 120 employees can now manage up to nine different machines when following a workpiece all the way to final assembly.
“I’m 90 percent happy,” Hütter says, and adds with a crafty smile: “But when a conservative German engineer talks about 90 percent happiness, those in other countries would probably be up around 270 percent!”
Originally published in Metalworking World 3.2011, a business magazine published by Sandvik Coromant.