Industrial production is on the brink of a fundamental transformation. German industry and society alone consume nearly three times as many resources annually as can be regenerated. This linear economic model not only leads to massive environmental impacts but also to a dependence on volatile primary raw material markets.
The circular economy model aims to close these material loops. Whilst remanufacturing is already established in the aviation and automotive industries, low material values, high labour costs and an enormous variety of product variants present major economic challenges for the mechanical engineering and electrical industries.
This is where the Circular Product Creation (CIRCE) innovation network comes in. The aim is to promote the reuse of used components by integrating remanufacturing and product generation development for the relevant industries.
Integration rather than isolation
The core of the CIRCE project lies in moving away from traditional remanufacturing, where parts are usually simply re-assembled into identical products. Instead, components are integrated into entirely new product generations using digital product instances. This approach requires close integration of recovery processes, reverse engineering, product development, and production planning and control.
Managing uncertainty in logistics
According to the Institute of Production Systems and Logistics (IFA) at Leibniz University Hannover, the key challenge lies in the inherent uncertainty of circular supply chains. In contrast to traditional manufacturing, where material flows are mostly linear, remanufacturing gives rise to reverse flows.
The flows of end-of-life products are characterised by uncertainties regarding the time of arrival, the quantity and the specifications of the components (geometry, condition). This uncertainty must be taken into account in production planning and control, which is why new planning, control and design methods, as well as integration with disassembly, inspection and development, are essential.
Consequently, during the course of the project, the IFA has set itself various objectives regarding the forecasting of return behaviour and data-driven process planning and control.
The research focuses on various aspects in this regard:
A forecast of the return behaviour of end-of-life products and components that are theoretically suitable for remanufacturing forms a crucial basis for the design of production systems and production planning. For this reason, one of the IFA’s objectives is to develop a reliable forecasting model for the return behaviour of components. Taking into account dismantling, inspection, market and return data, it should predict when and in what condition specific quantities of components will be available.
Furthermore, it is necessary to assess whether a used component is suitable for reintegration into a new product generation, taking into account availability, refurbishment costs and functional added value. This decision requires a multi-criteria suitability assessment that aggregates the available information from the areas of disassembly, inspection, development and production planning, thereby enabling transparent decision-making. A suitable approach for this is cluster analysis, which is used by the IFA for this purpose, incorporating historical production data and data generated by other work packages from CIRCE.
The final sub-goal of the IFA involves planning the disassembly process and the subsequent production process in close integration with product development and disassembly, as the high level of flexibility required in terms of volume, geometry and product variants for remanufacturing calls for new methods of production planning. For this reason, we at the IFA are developing new approaches to implement circular production in a way that is optimised both logistically and in terms of sustainability.
Synergies within the innovation network
The IFA’s research work is no more an isolated process than is remanufacturing in conjunction with product generation development.
The targeted traceability forecast model, for example, utilises inspection data (conditions, defects) generated by the Institute for Software and Systems Engineering at Clausthal University of Technology and provides part of the planning basis for automated disassembly by the Institute of Assembly Technology and Robotics at Leibniz University Hannover.
The results are incorporated directly into the work packages for product development at the Institute of Mechanical Engineering at Clausthal University of Technology and non-planar 3D printing at the Institute of Design and Applied Mechanical Engineering at Ostfalia University of Applied Sciences, for example to manufacture necessary interface components for reintegration into new product generations.
Added value for industry
For businesses, particularly small and medium-sized enterprises, the CIRCE research project offers a wide range of significant benefits. The industrial benefits of the project lie, for example, in combining AI-supported return forecasts with circular product design to shape the transition to a circular economy in a way that meets current needs whilst ensuring sustainability for the future. Manufacturing companies thus benefit from a significant reduction in primary resource requirements, whilst simultaneously reducing waste generation and increasing the proportion of secondary raw materials.
Beyond environmental sustainability, this approach reduces strategic dependence on critical raw material suppliers and strengthens the resilience of industrial value chains. Through the targeted transfer of results in workshops, approaches to improving environmental and economic sustainability are demonstrated, and practical solutions for implementing the regulatory requirements of the Green Deal are provided.
The IFA is therefore making a significant contribution to Lower Saxony’s RIS3 strategy through the CIRCE project by integrating production planning and control more closely with remanufacturing, with the aim of establishing a competitive circular economy in the mechanical engineering and electrical industries.
