Assembly: Customer-specific buses on four lines

Installing the interiors of the minibuses is particularly labour-intensive. Including pre-assembly operations, around 100 personnel are engaged in this. Production is on four lines, depending on model series and the work required.

Preassembly work is carried out in the same production shop, in parallel with installation. This is where the flooring is cut to shape by machine, windows are delivered on a vehicle-specific basis, instrument panels are prepared for additional, bus-specific controls and the vehicle electrics are prepared with an individual wiring harness. Ceilings, luggage shelves, air conditioning ducts and panelling are pre-assembled. Not least, the personnel carry out modifications to the powertrain, prepare the doors, grab rails and partition walls, and make the seats available. Delivery to the relevant assembly station covers short distances, using pallet trucks on a lateral supply basis.

Extensive procedures covering eight work cycles

The assembly process for each bus consists of eight cycles, each with extensive working procedures. It begins with adhesive bonding of the flooring in the required decor, and installation of the windows and roof vents. This is followed by installation of the electrics and a high-level station. This is where underbody work is carried out on the chassis, e.g. modifications to the powertrain, installation of the retarder, rear axle, fuel tank and exhaust system. This above all involves installation of the components and parts that were initially removed when the panel van or chassis was first delivered.

Back on level ground, work continues with the interior panelling including luggage shelves and air conditioning ducts, convector heaters and doors, plus their power supply. The interior fittings are completed during the last two cycles. The main items are the seats, grab rails, partition walls and curtains. Service fluids are checked and the batteries are installed.

Finish: Meticulous checks before an extended test drive

The finishing and final inspection stations await the new minibus after assembly. If included, the destination display is defined and programmed at this point.

Each individual bus is subsequently subjected to rigorous checks. This even extends to verifying the distances between seats for approval purposes. Not least, the personnel verify the quality reports from every assembly station. Even then, the process is not yet at an end: every minibus is sent on an extensive test drive. This takes place on public roads and takes around half an hour. A waterproofing test is also mandatory if modifications have been made to the roof. Only then is the bus given a final inspection and acceptance. The new bus is delivered either to the customer or to the relevant sales office. Depending on the model and level of equipment, between ten and 35 days will have passed since production commenced.

Intensive quality checks even after delivery

Quality is the watchword in production. As in all the company's plants, the global product audit system GPAS is used as the assessment principle. In this process, quality is precisely measured using comparable key figures. All production processes are subject to quality controls which are independent of production.

The quality of minibuses from Dortmund unreservedly meets the level of their larger siblings bearing the Mercedes star. This is also confirmed by the customers. Six weeks after delivery, customers are asked to give a satisfaction rating by an external service provider. The results are relayed to Dortmund for intensive evaluation.