| Written by Christian Aadal
The Vehicle Manufacturing Process in Four Stages
The initial stage is the press shop. The stamping facility supplies the sheet metal components for the bodywork, and the manufacturing process starts with heavy rolls of steel and aluminium sheets, known as coils. In the coil systems, the bands are cut into boards and then processed with fully automated high-speed servo presses, bent and punched in several steps, resulting in parts like side frames, doors, hoods, and roofs. This production lays the foundation for the unique design and exceptionally rigid yet lightweight vehicle bodies.
The second stage is the body shop. The body shop involves the precise assembly of several hundred individual parts made of steel and aluminium into a precision body. Depending on the vehicle requirements, carbon and fibre composites (SMC) are also used. With technical expertise from welding and joining techniques such as spot welding, soldering, screwing, and glueing, as well as new laser welding, bodies are created. Advanced robots perform these critical tasks with precision while skilled workers operate and maintain the machines. Production can be highly automated (up to 95 per cent) with spot welding, where robots weld points at predetermined locations on the body.
The third stage is the paint shop. Few details of an automobile impact the senses as strongly as the paint colour. It also serves to protect and preserve the vehicle's value. First, the bodies are cleaned in plunge pools and degreased, then coated with a zinc phosphate layer for long-lasting corrosion protection. Then, four more coats of paint are applied to shield the vehicle and give it a durable gloss. Eventually, paint quality is inspected after each production step.
The fourth stage is the assembly shop, where experienced personnel complete the painted bodies. During assembly, even unusual customer requests can be fulfilled. Various equipment, attachments, country versions, and more result in customised products. Often, several thousand interior variants are possible with just one car model series. Due to these possibilities, it is rare for two identical vehicles to come consecutively on the assembly line. In the final assembly, known as the wedding, the drive unit, including the engine, transmission, axles, and exhaust system, is precisely matched to the corresponding body and bolted together. The coordination of these components determines driving pleasure. Now, the vehicle stands on its own wheels. The final parts are installed, and the engine is started for the first time. After numerous tests, the new vehicle rolls off the line.
The Trend Toward Vehicle Customisation
Due to robots' high speed and reliability, a factory assembly line can produce up to 1,400 car bodies daily, which are then moved to the outside of the plant. However, since modern times, both individuals and corporations have been modifying and converting their vehicles for better comfort or functionality.
The primary reason for vehicle customisation is necessity. People often need more readily available, adaptable solutions or desire greater comfort and satisfaction than standard products provide. Consequently, it's not surprising that vehicle customisation has always been a trend in the automotive industry. Multiple 'trims' or 'versions' are offered when purchasing a car, varying in mechanics, exterior looks, and interior comfort. The price differences between these modifications can be significant, often confusing buyers and pushing them over budget. These preset packages come with a 'take it or leave it' approach, lacking more targeted customisation options.
However, vehicle customisation addresses this gap. It typically involves three areas: engineering or mechanical conversions, exterior or cosmetic conversions, and interior or comfort conversions.
Engineering and interior conversions are sometimes done during assembly in the factory, thanks to flexible processes, workforce, and tools exemplified by the Toyota Production System. Third-party companies also offer unique conversions for vehicle owners (see also: the vehicle processing center).
Some finished car conversions are performed within the factory due to reasons of flexibility and timing. Not all cars are produced to order but are manufactured for the market. Once an order is placed, the car can be customised for specific needs, including country requirements, season, tyres, and equipment packages.
The Finished Vehicles Area at OEMs
All vehicle manufacturers have dedicated areas for finished cars at their facilities, sometimes with capacities exceeding 10,000 vehicles. Why are these areas necessary for manufacturers?
Post-Production Modifications on Cars
Manufacturers must often modify vehicles post-production to meet specific customer requirements or comply with local regulations. These modifications can include installing add-ons like GPS systems, specialised lighting, and other customisations. Handling these modifications promptly and cost-effectively is crucial, requiring specialised equipment, trained personnel, and coordination within the finished vehicle department to ensure specifications are met.
Storage of Cars
Storing vehicles is another major task of finished vehicle logistics. After production, cars may need to be stored before transport to their final destinations for various reasons, such as waiting to fill a transport truck, clearing customs at a port, or awaiting dealership space availability. During this storage period, vehicles must be kept secure and safe from damage or theft. The storage area must be organised and efficiently managed to allow quick and easy access when it's time for transport.
Effective storage is vital in the finished vehicle logistics process to ensure vehicles reach their destinations in optimal condition.
As seen, finished cars are not standing idle. Because of post-production modifications, they are constantly moved at the premises to the garages back and forth. This movement involves several aspects:
- The team of drivers who deliver and pick up the vehicles
- The search and localisation of specific vehicles in the storage area
- The identification of the vehicle at the garage or other stations
- The documentation of work done at the vehicle
- The current status of the vehicle
A central vehicle management system where every unit is listed and maintained is the central point of handling such a large number of vehicles. But this system alone can't do the work. It is an extensive database reliant on constant input, manual or automatic, to be kept actual and, therefore, useful.
For sure, manual input is simple to implement: You need a keyboard and a terminal to add data like the vehicle identification number (VIN) and the current location. Barcode scanners usually accelerate the process and decrease erroneous input. And in the end, your database is constantly fed with data about vehicles and their status, adding record lines about what has been done by whom. This is, of course, theory because we know there is no perfect world for manual steps in data capturing: Data gets missed, capturing is forgotten or was done wrong. That's why we strive for improvement and, as a consequence, try to erode the potential source of error: the manual identification and capture of data. Automating identification and data capturing (AIDC) is the norm in industry 4.0 processes these days, but not self-evident in finished vehicle logistics.
Case study: Finished Vehicle Logistics at Volkswagen Wolfsburg
In all vehicle manufacturing plants in the world there is a certain point in the process where the vehicles are moved from the conveyor belt production to be driven by operators, in Volkswagen Wolfsburg this point is called Zielpunkt 7, or Checkpoint 7.
In most cases, the vehicles are driven directly to the parking yards. At the entry to the yard, the driver gets handed an RTLS transponder that has already been associated with the Vehicle Identification Number and gets placed in the rearview mirror.
Each driver also gets a designated parking spot to place the vehicle, let's say, Row 15, Spot 27. However, since there might be misunderstandings and interruptions, there is a probability that this spot has already been taken by someone else, which causes the driver to place his vehicle in a nearby free spot.
If they would rely solely on planned data (where the vehicle is suppose to be) this would lead to a complete mess when vehicles are to be picked up.
However, since they have the RTLS transponder in the vehicle, they always ensure that the actual spot of all parked vehicles is reported in the system. It shows the real value of planned data versus actual data.
When a vehicle is picked up from the parking yard it goes directly into what is called the finishing process. Some of the tasks in finishing is washing, fuelling, body repair, electrical repair and mechanical repair.
Throughout the finishing process, there are strategically placed checkpoints where each vehicle are being detected by an RFID reader. With this data, they can get measurable data for their KPIs and make sure there are enough workers on a shift.
The RFID is also integrated in the fuelling process. Before RFID was involved the workers always had to manually fuel an exact amount depending on the vehicle type, this usually led to over fuelling. Imagine if each vehicle gets 1 liter of fuel more than it is suppose to have and every day 3000 cars gets fuelled. This results in 3000 liters of over fuelling, which cannot be charged to any customer.
After the RFID technology was taken in use, all the worker has to do is scan the transponder at the fuelling station so that it knows the model and type, and the station will automatically stop the fuelling exactly on the correct amount.
These use cases are only a few examples, but they show the real value of actual data in the process of handling finished vehicles.
Read more about the Volkswagen factory in Wolfsburg and car logistics ...
Takeaway
RFID technology plays a crucial role in automating finished vehicle logistics by ensuring precise tracking and management of vehicles post-production. At Volkswagen Wolfsburg, RTLS transponders linked to each vehicle's identification number accurately record the vehicle's location, preventing misplacements and facilitating efficient retrieval. RFID readers strategically placed throughout the finishing process monitor vehicle status, optimising workforce allocation and ensuring timely completion of tasks like washing and fuelling. The automated fuelling system, which adjusts fuel amounts based on vehicle type, exemplifies how RFID reduces errors and operational costs, highlighting the importance of actual data over planned data in logistics.
Delve deeper into one of our core topics: Car logistics
Author
Christian Aadal, Product Manager
