The "5-day factory": A unique recipe for success

Solutions of this kind are considered routine in the automotive sector, where high volumes are the norm. In the rail vehicle industry, however, where production tends to be geared towards small volumes or one-off production, this concept is an absolute novelty.

The most important element of the five-day principle is the drastic reduction of internal production throughput times. The production and work organisation processes have also been aligned with this. Knorr-Bremse Budapest was breaking new ground at the time. In the past, for example, the production of a block braking unit was expected to take 15 to 25 working days from the provision of the raw material to final assembly and testing. In the five-day factory, the entire production process has to be completed in five working days, which takes about 20 to 25 per cent of the time previously estimated. At the same time, the quantity of materials tied up in the process and thus the inventory values are reduced to a quarter of the original quantity.

The changeover to the new production process offers Knorr-Bremse's customers enormous advantages: customer orders are processed more flexibly and reliably than before, changes can be implemented more quickly, capacities are used optimally, and the efficiency of the supply chain has been improved. Last but not least, the use of state-of-the-art development techniques ensures that customers receive products that meet the highest quality standards.

• Too much was produced too early, resulting in excess production.
• The formation of large batches subsequently led to capacity bottlenecks and reduced flexibility in production. (Model mix production)
• A lack of object dependencies between component production and final assembly led to overproduction at the component level.
• Unexpectedly high demand in certain periods led to capacity overload at the supplier and thus to a lack of component availability.
• Increased effort for capacity levelling
• High effort in control and schedule tracking. No stable process chains.
• Lack of production resources and tools availability when order sequences change.

To achieve the objectives of the five-day factory, it was necessary to change system settings such as the lot-sizing procedure on the one hand, and to adapt the SAP tools for production planning and control to the objectives of the five-day factory and the planned Heijunka process on the other.

The graphic planning table was used for precise planning and control of the assembly and mechanical production. In the first step, the bottlenecks in the individual production lines in the assembly were analysed and realistic times were assigned in the work plans. This enabled finite planning of the lines. With the help of the graphical planning board, the individual assembly lines can now be optimally utilised, taking into account the actual capacity situation. Based on the scheduled orders, the requirements are then planned via the MRP and order proposals (planned orders) are generated. To ensure that only those parts are produced in mechanical production that will actually be assembled in the following days, only planned orders whose pegged requirements have actually been scheduled can be converted into production orders, i.e. a production date is actually planned in the assembly. The planning of the mechanical production also takes place via the graphical planning board in order to achieve a realistic utilisation of the machines.

In order to achieve the goals of the 5-day factory in mechanical production as well, a transaction was designed and implemented that only allows planned orders to be converted into production orders if the requirements originators are actually scheduled in assembly and thus a concrete requirement exists and production is not only for stock. The functions of the graphical planning board described above are also used to some extent in mechanical production to enable optimal planning and control.