Small series and prototype production at ZF Friedrichshafen AG create new challenges for quality control time and again: measurement programs for new components need to be created every day. ZF metrologist Mehmet Akol accepts these challenges with unrelenting curiosity and uses ZEISS training courses to help him.
Whether it’s parts for a bus, train, or ship, small series and prototype production at ZF Friedrichshafen AG manufactures a wide range of driveline and chassis technology. What’s special about it? The batches have between one and 50 units, and the requirements on the individual components are high. Prototypes must be quickly executable, and functioning parts have to be sent to the customer at a moment’s notice. That’s why quality control is so vital in this line of work.
“Measurement programs are compiled centrally for series production,” said Uwe Ersing, head of Quality Control for small series and prototype production at Commercial Vehicles and Special Driveline Technology. “My staff have to compile new measurement programs on an ongoing basis, and different requirements apply to different components. Gearboxes for marine technology, for instance, are subject to the regulations of the classification societies. This results in strict specifications for documenting measurements.”
A total of 32 employees, 13 of them metrologists, are responsible for quality control. Akol is one of them. For the last seven years, he has been working in metrology and is motivated by the ever-changing requirements.
Thirst for knowledge
Akol joined ZF Friedrichshafen AG 10 years ago and initially worked in gearbox production. Every day he was faced with measurement results for quality inspection. If these conflicted with the results produced by his processing center, Akol wasn’t satisfied with simple explanations.
“I always wanted to know where the measurement results came from and why they turned out the way they did,” he said. “I constantly asked about this, and that’s why I drew so much attention to my quality inspections.”
This prompted Akol to switch to metrology three years later; he’s not easily satisfied with his measurement results here, either.
“Everyone can share a result, but you have to know how it came to be and how you should evaluate it,” he said. “Only then can it be valuable for the others.”
He always questioned processes and results and wanted to find out the background to them. His curiosity led him to attend his first AUKOM seminar at ZEISS in 2014, which he followed up with AUKOM Stages 2 and 3 and AUKOM Form and Location. He also attended further seminars on CALYPSO, GEAR PRO, and on offline programming. He even received training in a special subject: the Fourier analysis.
Consistent, continuous training
Even though Akol has attended many seminars and has a folder filled with certificates, he’s by no means done. A metrologist’s thirst for knowledge seems to know no bounds.
“Standards and drawing specifications change, and software is further developed,” he said. “Time and again I see components and I wonder if they’ve been perfectly programmed.”
Ersing, who joined ZF 38 years ago, has noted a great interest for further training and development among his younger employees — and he supports them wholeheartedly.
“We must never stand still,” he said. “The demands made on our industry are changing far too quickly.”
That’s why further training has a special place in quality assurance at ZF. Every new metrologist who works on 3D coordinate measuring machines spends their first six months working on further internal training measures before completing AUKOM seminars 1 and 2. In an attempt to become more efficient and bring together metrologists from different sites and areas, ZF now holds these training sessions on site. Twice a year, AUKOM seminars for Stages 1 and 2 are in Friedrichshafen and conducted by a ZEISS instructor.
Standardization and communication
Ersing sees a great advantage to this type of further training: namely, standardizing quality inspections.
“It’s important that our measurement programs are structured in the same way,” he said. “Without such consistent training, 10 metrologists measuring the same component could provide us with different measurement results.”
The seminars offer a further benefit for quality assurance in small-series production: communication and teamwork with Production has improved dramatically as a result. If the measurement results are questioned in Production, the metrologists can explain them much better to their colleagues, and justify them, too. This has also enhanced teamwork between the two departments. It also means that metrologists are now involved in problem-solving more often in order to check where potential error sources could be.
“Components and drawings are becoming increasingly complex,” Akol said. “If a metrologist finds out that the measuring result is not OK, they will first take a close look at the result and not the component. That’s what used to happen to me, too, and it’s why good communication is so vital. I work with my colleagues from the processing center to find an optimum solution.”
That’s exactly what he loves about his job.
“I need the daily challenges associated with working in quality assurance for small-series production,” he said. “It’s always exciting to compile a measurement program for a new component. It’s important to note the special features of the component, position, and secure the component correctly on the measuring machine, and define the different parameters, such as measuring speed. This normally also has to happen to relatively tight deadlines. This limits the time we have for the measuring job and demands an optimized process for the measuring program. Then again, the more complex the job, the more fun it is.”
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