The central problem is that even the OEM´s are not yet in a position to make clear and reliable statements about the required output of the system. If the machine is designed for the output for the pre-planned, final cycle time and the forecast performance peaks are ultimately not called off, enormous costs are incurred because the assembly concept does not pay off. This means that as a machine builder we have to provide our customers with a production machine that is as flexible as possible.
Ms Schauberger, what is the problem with the call-off figures?
What do you have to consider when developing the concept with regard to the required flexibility?
In automation, easy expandability required. This is already given by our various AKE standard cells. At the request of our customers, however, we already pay attention to later expandability during the conception and design - for example, ideal separation points are created, mounting patterns for expansions are provided and concepts for later expansion stages or for additional product variants are developed.
In terms of flexibility, the worker activities also must be considered.. A important point is to design the arrangement of the operator positions and also the timing of the manual work - i.e. as flexibly as possible. Thanks to our many years of experience in designing flexible assembly concepts, also in the crafts sector, we are happy to advise our customers on the arrangement and ergonomic and efficient design of workplaces.
How exactly can you imagine the efficient design of work activities or workplaces?
The aim is always to achieve easy scalability of the system. In the peak year, the maximum number of employees is needed. The start-up phase or the end-of-life phase, i.e. the supply of spare parts, is only covered with a minimum number of employees.
In our concepts for manual pre-series production, for example, we work with scaling of the quantity of operators. But also the output of an automated line can be adjusted in this way. In order to produce the desired number of parts with less employees in the start-up phase, several activities can be combined through intelligent workplace design.
By arranging the assembly line in a U-shape, worker and packaging stations are combined as much as possible to shorten walking distances. In this way, one worker can operate several stations.
With the so-called "Chaku-Chaku principle", it is also very easy to operate the line with a reduced number of workers in the ramp-up and ramp-down phase. With this method, the workers pass through the stations one after the other in a predefined sequence - the number of operators depends on the required line output.
Doesn't operating multiple stations mean a lot of work for the worker in the plant?
Of course we think about how we can relieve the worker in this phase and make the work at several stations as easy as possible. The best way is to decouple the workers by feeding the individual parts via belt conveyors, linear conveyor lines or accumulating conveyors. In this way, a certain product variance can be covered as well as the influence of the workers on the production process can be reduced. The workers can build up a buffer through decoupling and thus operate several workstations without any problems even in the start-up or end-of-life phase.
At some point, it is no longer just about the workers' workstations. You have already briefly mentioned the expandability of the systems themselves. Do you have any concrete examples of this?
Yes, of course, for example, an manual transfer system can be upgraded to a automatic workpiece carrier system. Integrating processes and activities into an automated cell also reduces the operator's workload.
For the sace of simplicity, let's assume a screwing process that is initially performed manually with a bit change and an existing manual screwdriver and then upgraded to an automated station. The operator is relieved and can take care of simple assembly tasks, which in this case would be more cost-intensive to automate, and the automation takes over the quality-relevant screwing tasks. Undoubtedly, this must also be economical: For a single screw, this procedure is certainly unprofitable, but if several screwdriving operations can be carried out with the same type of screw, it is worth considering.
In any case, it must be weighed up to what extent the activity of the employees should be reduced. This depends on the one hand on the production location and on the other hand if it is possible to automate processes and activities cost-effectively.
What is the easiest way to realise such upgrades - and above all with minimum downtimes?
The easiest way to design upgrades is - as already mentioned - to take them into account already in the basic concepts by planning ideal cut-off points or mounting patterns. This applies both to the product variance and to the planned cycle time reduction. In the expansion stages, the manual work of the employees is also taken into account again and, if necessary, redesigned.
In the expansion stages, individual process modules can be adapted to an existing machine frame, for example. If no empty spaces are to be pre-planned, complete standard cells can be integrated in modular design.
By pre-planning expansion stages, the machine downtime during expansion and the associated necessary prefabrication of components can be significantly reduced. This can even go so far that we prepare and stagger the upgrade in such a way that it is possible to produce in some shifts during the comissioning oft he upgrade.
What advantage does it offer your customers to initially cover planned call-off figures with expansion stages? Is this approach really practicable?
Since it sometimes takes years from SOP (start-of-production) to peak output, it is definitely a practicable solution to cover the quantities in the start-up phase and only then invest in the final expansion stage.
With this approach, our customers have the opportunity to re-examine the market situation after the product start-up phase and adapt the plant technology to the current requirements.
With this procedure, the initial investment can be kept low. It is common practice to expand automatic stations or even manual stations at a later date. Such expansions are always possible in principle. However, they are much easier, faster and, above all, cheaper to realise if they are already taken into account in the basic concept.
What advice can you give your customers?
It is becoming increasingly important and is definitely a challenge to find the right balance between an initial situation that is secure in terms of investment and sensible preparation for later expansions.
Here, our customers must also be willing to invest in a flexible design at the beginning to make the extensions as simple as possible later on. If the extensions are already taken into account in the planning phase, this has a positive effect on the later costs of the extensions and the downtimes during commissioning of the extensions. This applies equally to an increase of the production quantity or a variant upgrade. Only together with our customers can we react with the necessary flexibility to rapidly changing market situations.