The conveyor belt, which has determined the speed of production for more than a century, especially in the automotive sector, seems to have reached its limits at the point where today's technology has reached. Numerous variants and customization options make tools more and more diverse. This naturally causes processes and components in assembly systems to become more variable. Dealing with this complexity is also becoming more and more difficult.
To overcome this, Audi introduces the world's first modular assembly system in the automotive industry as a new and complementary form of organization: Modular Assembly
Increasing complexity in products and demand today also changes production requirements. This creates the need to adapt to customer-specific needs, short-term market changes and sustainability issues with greater flexibility than ever before. As a result, mapping a conventional conveyor belt assembly is becoming increasingly challenging. Doing things this way is based on the principle of uniform cycle time for each product, in a fixed order. The Modular Assembly that Audi is developing works without belts or a uniform running speed.
Modular Assembly, one of Audi's answers to future production demands, replaces rigid conveyor belts with dynamic procedures with a variable station array, variable processing times (virtual conveyor belt). The concept model is already being used for pre-assembly of interior door panels at the Ingolstadt plant, in preparation for the next series of applications. The pilot project, which is considered as the most important example of Audi's development of networked production in agile teams and innovation culture, offers more flexible and efficient assembly.
One of the most important advantages of the flexible system is that it allows the employment of workers who are no longer able to work on the line due to their physical limitations. Audi uses more flexible automation in the production process to ease the burden on employees. Instead of a uniform cycle, all workers get a lighter workload thanks to variable processing time.
In the tests of the pilot project, the tasks do not follow a uniform order. Instead, they are configured to meet specific needs. Automatic guided vehicles (AGVs) bring the door panels to the station where the components are to be installed. For example, light packages are installed at a station with cables and lighting elements. Jobs without a lightweight package skip that station. At another station, a worker assembles the optional sunshades for the rear doors. On the pre-scheduled conveyor belt, these tasks were split between two or three workers, which could be relatively inefficient and compromise quality. When jobs pile up at one station, AGVs take the product to the next station with the least possible waiting time. The project also cyclically checks and adjusts the configuration of the workspaces. Unlike a conveyor belt, the stand-alone stations and modular production system can be operated efficiently in a specific spectrum (optimal operating range) instead of the optimum operating point.
In cases where component variability is high, the principle that the solution varies from person to person disappears in this project. AGVs can be routed down to a centimeter via a radio network. A central computer guides the AGVs. In addition, camera inspection can be integrated into the quality process. In this way, irregularities that can be experienced on a conveyor belt are eliminated and can be managed more quickly and easily. Thus, it also helps to avoid unforeseen additional labor.
The pilot project is geared towards value creation and self-management, reducing production time and increasing productivity by around 20 percent. Making it possible to reschedule jobs effortlessly by disconnecting stations, the system often only needs software tuning, thanks to flexible hardware and automated guided tools. Stations can be adapted more easily than an interconnected conveyor belt according to products and demand. Audi aims to integrate Modular Assembly into larger scale assembly lines as the next step.