Models for Modular Assembly

The market for power tools is particularly tough, with differences of sometimes less than one euro per device determining a manufacturer’s competitiveness. At the same time, products are rapidly becoming more individualized and the quantities ordered are dramatically lowering. Companies who can adapt their production to these framework conditions and react quickly to customer requests will win orders. Up until five years ago, manufacturers could plan with an average batch size of over 2,000 units. Today, due to smaller order sizes, systems often have to be retooled to make a different product after less than 300 units. 

This has consequences for almost all operational areas of companies in the power tools industry. Starting with production technologies: The degree of automation must be drastically increased, even for small quantities, while at the same time reducing set-up times to a fraction of what they used to be – and all of this in an economical manner. This leads to significantly more time- and resource-intensive processes for production planning teams, as smaller batch sizes with many variants entail much more control effort than highly scaled mass production. Since this results in significant change dynamics, procurement and sales logistics processes as well as the entire holistic production management must be fundamentally redesigned. 

Reorganization of the process landscape

Against this backdrop, a global manufacturer brought experts from Fraunhofer IPK on board to support the adaptation of its process landscape. The idea of modularizing the assembly processes to make them future-proof became the starting point for a complete redesign of the production processes. Process dependencies make it necessary for a new production technology to be followed step by step by adaptating control processes, logistics, management processes, supplier management, and factory IT. Both the company and the Fraunhofer IPK team realized from the outset that due to market dynamics, a traditional sequential approach was not an option. It was therefore decided that joint teams consisting of employees from the company and Fraunhofer IPK would develop innovations at all levels of the new factory structure simultaneously in five parallel project streams. 

One of the teams developed an innovative method for modularizing assembly, which allows new products to be manufactured on modular systems within a short period of time with little adjustment effort and short set-up times. Another team ensured that the factory IT systems support rapid changeovers and rescheduling. A SOFT-SCADA was developed for higher-level control of the processes on the shop floor, which does not have to be reprogrammed but is configured using a model. The system can simultaneously control the machines, which are quickly combined into a line, and record data on their operation. The underlying model ensures that all systems, from enterprise resource planning (ERP) functions to machine control, are seamlessly integrated yet flexible. Another working group transformed the holistic production system so two goals were reached: Employees could better internalize why the changes were necessary, and set-up times were reduced from over two hours to less than ten minutes. 

Blueprint for the factory of the future

Overall, the project managed to synchronize very different, yet closely linked innovation processes that often tend to interfere with one another, along with their respective risks. This success is based on a common corporate model for all innovation, design and implementation processes. In addition to the internal and adjacent value creation processes, this model also takes into account their control, the management processes and the plant assets – such as machine systems, individual machines and IT infrastructure – and not least the company organization with its roles and responsibilities. Within a month, an initial model was created, forming the common ground on which the individual teams could work in parallel and easily coordinate any fundamental changes. During the subsequent development activities, the model continued to evolve in a decentralized manner. It helped to quickly identify dependencies and assess the impact of technology solutions on other areas. Today, an integrated economic component of the model helps to ad hoc assess the impact of a new technology option. Consider, for instance, the question how the design of an assembly robot will influence the unit costs of the appliances produced with it. The integrating effect of the model has by now reached an extent where different simulation models are linked together in an intuitive way – for example, simulations from logistics with a kinematic robot model.

Five years after the initial idea, the modular system is already working in mass production, achieving an availability of over 99 percent and manufacturing products economically despite the high level of customization. The required factory IT is operational, from a new ERP system to a Manufacturing Execution System (MES) implemented for the first time and flexible system control with SOFT-SCADA. The most important thing, however, is that employees, from IT managers to workers or quality engineers, can take the next steps together using the integrated model. This includes, for example, deriving a Blueprint Plant Model (BPPM), which can be used to implement sister plants anywhere on the planet applying the developed model in such a way that they are optimally adapted to the respective market conditions and are still very similar. The team currently tasked with setting up a new plant would like to use the BPPM as a basis for implementation for all partners as early as the beginning of 2025.