Behind The Scenes: From volume production to the aftermarket

High product quality ensures competitive success. A look behind the scenes at production and quality assurance at ZF.

A dictionary definition of the term “quality" may refer to the characteristic traits or the condition of an item. Some definitions may include the notion of “excellence” later on. Not at ZF though. Here excellence comes front and center. Highest product quality has top priority – and does so across the entire product lifecycle of the ZF components.

A glance behind the scenes at production at ZF shows the meticulous approach adopted from the initial production step right through to the very last manual check. Even during the development process, the details for quality assurance are also stipulated alongside function and robustness. This starts right from the selection and specification of the suppliers' scope of services. Supplied components are subjected to a target/actual comparison using a 3-D scan before they are transferred to production.

Millions of parts – uniform quality

A look behind the scenes of the electronically controlled damping system CDC production.

The manufacturing process for, say, the electronically controlled damping system CDC (Continuous Damping Control) is almost entirely automatic, but nonetheless manual intervention is required at certain stages. 1.4 million CDC dampers were produced in 2014 alone at the location in Schweinfurt. A data-matrix system ensures that the individual manufacturing steps can be traced for each individual product. A high-tech system uses electronic image processing and a high-precision laser to check each module in order to determine whether all components have been assembled correctly and whether material defects or other potential defects are present. The tests are not conducted on selected samples; instead a thorough check is run on every single part. If the system detects an error, the affected part is immediately discharged from the process and the root cause analyzed.

Precise procedure – whether by machine or by hand

Also 1.4 million DMF were produced in Schweinfurt in 2014.

Detailed quality checks are also incorporated in the manufacturing process for the dual-mass flywheels (DMF). Even during the manual insertion of the internal components, a camera checks the condition and fit of all parts. Before the spring assemblies inserted by a robot are installed, a camera checks the correct positioning. Once the primary and secondary flywheels have been welded, the seal is tested using helium on a compressed air testing system. Before the customer-specific packaging and delivery, an employee manually rechecks everything according to criteria such as concentricity, the laser labeling, and for any possible visual damage.

Quality assurance also in the spare parts business

ZF Services proceed the quality tests for the aftermarket.

In addition to numerous testing and monitoring steps during volume production, quality tests once again take place at ZF Services before and during distribution to spare parts dealers. Before storage at one of the 72 logistics centers worldwide, the components are subjected to an incoming goods inspection before they are sent to the next stage of distribution at the wholesale and service partners. If product-specific or transport-specific defects are discovered, additional testing takes place immediately, such as the testing used in volume production. Using sophisticated, contemporary testing techniques such as 3-D coordinate measuring machines, function test benches, or 3-D scanners for the measurement of contours and the simulation of sequences of movement and functions, ZF Services not only has the necessary know-how but also a variety of quality assurance technologies. “Within our company, we do our utmost to ensure best quality along the entire process chain,” says Helmut Ernst, Chairman of the Board of Directors, ZF Services.

In addition to spare parts in OE quality, ZF Services partners also benefit from appropriate, requirements-based service offerings, such as assembly and service information, technical training and product training courses, or the detailed workshop concept [pro]Tech.

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