Investing €500m to expand its operation at Leipzig means that, for the first time, Porsche can take three models on a single route through identical stations
Since production of the Macan began in 2014, Porsche Leipzig has operated as a fully-fledged production facility with a modern paintshop and a dedicated bodyshop. For the Panamera, however, bodies-in-white were manufactured and painted at the Volkswagen factory in Hanover before moving to the Saxony plant for pre- and final assembly.
Now, to accommodate complete production of the new generation Panamera, Porsche’s second home has expanded for a fourth time in its 16 year history, gaining a new 56,000 sq. m bodyshop. The €500 million project also took in assembly line adaptations and infrastructure upgrades with, in all, 600 additional jobs created. The sure and steady growth, however, hasn’t affected the company ethos or the production model. Leipzig works to the same Porsche principles as its sister plant in Zuffenhausen, near Stuttgart, which is home to the 911. The brand’s philosophy reaches back to the founder of the company himself, Ferry Porsche, and his belief in ‘always getting the most out of everything’.
Christoph Beerhalter, general manager at the Panamera bodyshop explains: “The distinctive features of production here are transparent processes [and] the consistent implementation of the principles of lean production.”
"Aluminium is a demanding material. Using the buffing pads and polishing techniques heat is generated and it might deform the material, it takes skill to avoid that." - Christoph Beerhalter, Porsche
Small stockholding for a just-in-sequence method controls delivery of pre-assembled and model-specific components in precise order of production and assembly time – in some cases directly to prescribed locations along the assembly line. Improvements are sought through constant reduction and elimination of waste, as well as continuous gains around processes while maintaining emphasis on the highest quality.
The first of the principles is flow – intelligent logistics and IT systems network all value-creating processes with one another. Porsche manufactures according to the ‘customer cycle’ – production volumes are the driver for all processes during the building of its cars. Employees in the assembly hall cyclically pull materials from logistics supply centres. Consequently, suppliers provide only the quantity of parts needed to meet the imminent demand, avoiding overproduction and unnecessary buffers. Finally, a zero-errors principle is an assurance of robust and stable processes and products free from glitches.
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High vertical integrationThe body of the Panamera is based on the Volkswagen Group’s flexible modular standard kit (MSB). Leipzig’s new MSB bodyshop is overseen by a factory control system that assigns a body-in-white (BIW) to a vehicle order number right from the first component. The body is made up of 430 individual parts brought together by thermal and mechanical joining methods, plus applications of more than 200 metres of adhesive. On average, 13 bodies are produced per hour in the MSB bodyshop. In all, 475 robots and 189 employees are needed for the construction of the bodies with a vertical integration of over 90%.
“Overall, the body consists of 45% aluminium,” Beerhalter says. “This high aluminium content requires an extremely high degree of competency in tool-making and surface finishing.”
Aluminium skinThe entire exterior skin of the new Panamera consists exclusively of aluminium. The vehicle body grows from the bottom up, in four major sections: underbody, superstructure, add-on parts and finishing. First, the platform of front body, floor and rear body are brought together to form the underbody line. Side panels and the roof are added to the underbody, then the construction process is divided into three major areas.
In superstructure one, the inner side walls are welded to the underbody structure. In the next section, superstructure two, the outer side walls are mounted – these are the sheets of the exterior, which make up the design of the Panamera. In superstructure three, the body is completed by mounting the roof.
The €500million investment created 600 new jobs and saw production at Porsche Leipzig rise to 650 cars per day
At the add-on parts line, the doors, boot lid, front wings and bonnet, which have been manufactured in parallel steps beforehand, are integrated into the body. Robots mount the doors and bonnet fully automatically as the tight gap dimensions and transitions between surfaces require automated work methods. Workers use a semi-automated process to assemble all the other add-on parts.
The fourth and final area is finishing, in which the body manufacturers check surfaces and perfect them if necessary, as well as fine-tune the add-on parts. It’s the section with the highest proportion of employees given the skilled hand and trained eye that’s required.
“Aluminium is a demanding material,” says Beerhalter. “It is quite difficult to finish parts as you have to be well trained in using the buffing pads and polishing techniques – heat is generated and it might deform the material as you put in heat. It takes skill to avoid that.”
The air conditioning not only keeps this busy and highly-populated line cool but draws air down to extract the aluminium dust the finishing techniques create. The operators and vehicles move on separate belts that incline, creating an optimum ergonomic working height to suit wing, bonnet, roof, etc.
“After that comes another quality check,” Beerhalter says. “Every body is inspected for our customer, which in this case is the paintshop.”
Power & performanceLeipzig’s solar power technology was first installed in the Macan bodyshop back in 2013. A photovoltaic system on the roof with a capacity of 880 kWp has been generating up to 800,000 kWh of electricity per year, equivalent to around the annual power consumption of 150 typical European households. Another photovoltaic system will supply the new Panamera bodyshop with a huge part of the electricity it requires, but will save four megawatt-hours of energy from conventional sources. Lighting throughout the new building is wholly based on LED technology.
Advanced network technology in the plant control system also helps to save energy. An adjoining co-generation unit is used for efficient heat and power generation. The new bodyshop processes and manufacturing systems have helped to reduce energy consumption. This is partly due to new energy-efficient joining technologies, for example by FDS bolts that need no pre-drilling.
Given the multi-material mix in the light bodies, riveting and clinching joining techniques help to significantly reduce the bodyshop’s energy consumption. All robotics and programming of the production facilities have been implemented to take account of energy efficiency.
“This applies in particular to the use of servo-pneumatics in the welding tongs,” explains Porsche’s director of production planning Thomas Riediger. “Selected components can now function without any compressed air, helping to consistenly reduce energy consumption.”
“There are more forward-looking changes in assembly,” Riediger says. Intelligent networking between the building, production facilities and the vehicles allows lighting control on demand in assembly as well. “Simply shutting down workplace lighting automatically during breaks can save 80MWh per year’, he adds. “Where possible, existing halogen spotlights have been replaced with LED lights with programmable control. Depending on the workload and vehicle type, lighting is provided only as needed so that energy can be saved sustainably.”
In addition, modern cooling technology in the robot welding guns reduces energy consumption in the Macan bodyshop by more than 365,000 kWh per year.
In the paintshop, a rock-flour filter system reduces energy consumption by 60% in comparison with a water-based system. At the end of process, Porsche continues to bolster its sustainable credentials as 70% of all vehicles from the Leipzig factory being transported from its onsite rail depot.