Transparenzsteigerung in der Rückführungslogistik zur Verbesserung der Materialbedarfsplanung für das Remanufacturing

Motiviert durch einen steigenden Ressourcenverbrauch und des damit einhergehenden Erreichen der Grenzen der linearen Take-Make-Use-Dispose-Mentalität sind innovative Produktionsmuster wie die Kreislaufwirtschaft erforderlich. Das Remanufacturing spielt hierin eine zentrale Rolle, wobei die Rückführungslogistik für die Versorgung dessen mit Gebrauchtprodukten (sog. Cores) zuständig ist. Trotz erheblicher Einsparpotentiale steht die Umsetzung aufgrund vielfältiger Herausforderungen jedoch erst am Anfang. Hierzu gehören u. a. der effiziente Informationsaustausch mit beteiligten Akteuren in der Rückführungslogistik und die anschließende Nutzung der Informationen, um das Remanufacturing zu optimieren. Am Beispiel der Materialbedarfsplanung, d. h. der Versorgung des Remanufacturings mit notwendigen Neukomponenten, entwickelt die vorliegende Arbeit eine Methode zur Transparenzsteigerung in der Rückführungslogistik zur Optimierung ebendieser. Neben der Modellierung des Material- und Informationsflusses erfolgt hierzu die Erarbeitung eines Konzepts instanzindividueller, dynamischer Regenerationsraten sowie die Gestaltung echtzeitfähiger Bestellpolitiken, die diese als Input verwenden und je Planungsperiode die Bestellmenge und den -zeitpunkt dynamisch anpassen. Zusätzlich wird das Wagner-Whitin-Verfahren als deterministischer Benchmark-Algorithmus integriert. Mittels Implementierung in einer simulationsbasierten Optimierung zur Identifikation von Wirkzusammenhängen sowie einer Nutzwertanalyse und der PROMETHEE-Methode zur Ableitung anwendungsspezifischer Handlungsempfehlungen erfolgt die Umsetzung der entwickelten Modelle. Die entwickelte Methode wird am Beispiel des Automotive Aftermarkets prototypisch validiert und erprobt. Anhand unterschiedlicher Stückzahlszenarien und Graden des Informationsaustauschs wird gezeigt, dass diejenigen Bestellpolitiken mit einer variablen Bestellmenge, d. h. die (t,S)- und (s,S)-Politik sowie die SM-Heuristik die besten Ergebnisse hinsichtlich der untersuchten Kennzahlen liefern. Die mit Hilfe der PROMETHEE-Methode abgeleiteten Insensitivitätsintervalle zeigen außerdem, dass die ermittelten Lösungen größtenteils sehr robust gegenüber Veränderungen in den Entscheidungspräferenzen sind. Zukünftige Forschungsarbeiten sollten den Nutzen der produktspezifischen Informationen für weitere Planungs- und Steuerungsaufgaben sowie die Gestaltung integriert linearer und zirkulärer Wertschöpfungsketten fokussieren

Product allocation and network configuration in global production networks – An integrated optimization approach

Driven by an increasing demand for individualized products and shorter product life-cycles, companies continuously extend their product portfolio. Simultaneously, companies expand into new markets to reach customers and to exploit varying location factors to reduce costs. Global production networks (GPNs) have to be adapted constantly to react to new circumstances and changes in the demand of products. To remain competitive, product allocation and production network configuration are essential. At the same time, companies face an increasing complexity while handling these tasks. This poses a challenge particularly for small and medium sized companies, which have limited planning capacities and management resources. Current literature describes optimization-based approaches for the integrated product allocation and network configuration of production networks. Yet, multi-objective models lack transparency of results and user friendliness. Therefore, this paper presents a multi-objective optimization model that incorporates flexibility and reconfiguration aspects to determine an optimal product allocation and network configuration of a GPN over a given planning horizon. The preemptive goal programming approach is used to identify Pareto-optimal solutions and to increase user friendliness. The subsequent verification, validation and post-optimality analysis combined in a structured process enables a wide range of companies to apply the approach. The model is successfully applied in the GPN of a special machine manufacturer, which produces high precision metrology machines. Due to its transparent approach for complex planning problems, the developed method provides a solid base for well-founded, objective decisions. Hence, the risk of costly errors in the planning phase is reduced

Approach for developing implementation strategies for circular economy in global production networks

Due to excess of resource consumption, circular economy (CE) aims to return products to the production life cycle in an economically and ecologically reasonable way. Yet, few approaches focus on the strategic and network level of CE. First, existing approaches regarding the configuration of CE networks and the development of appropriate business models are reviewed. Second, an approach on how to integrate both aspects is presented. By integrating these aspects, implementation strategies for CE in global production networks shall be developed facilitating strategic decisions. The approach is planned to be demonstrated in a German company supplying the automotive sector

A Circular Economy Strategy Selection Approach: Component-based Strategy Assignment using the Example of Electric Motors

The sustainability of industrial processes and products is a core issue of our time. There are several approaches to move from a linear, inherently wasteful economic principle to a circular economy focused on conserving products, resources, and energy. However, selecting which of the circular economy strategies ranging from reuse, repurpose, and remanufacture to recycling is crucial to ensure the economic viability of the product. This contribution proposes an iterative, component-based circular economy strategy selection method that supports product and production planners in choosing the appropriate circular economy strategy. For this approach, the suitability of each component for circular economy strategies is assessed based on identified key properties. In case of no fitting strategy, further component decomposition is devised, and the process is repeated. To further support the design of circular economy strategies, a modular process build set is suggested, enabling the swift composition of the processing sequence. The approach is then applied to the example of an electric motor of a battery electric vehicle. The presented approach allows a quick first assessment of the viability of different circular economy strategies and helps product and production engineers develop product-specific circular economy strategies

A systematic approach for simulation-based dimensioning of production systems during the concept phase of factory planning

Due to increasing globalization, market penetration, and technological progress, more products are becoming highly standardized and interchangeable. This has led to fierce price competition, forcing companies to compete for declining margins. To remain competitive in the long term, it is essential to consider both changeability and profitability during the early planning phases. The article proposes an approach for simulation studies using discrete-event simulation during the concept phase of factory planning. This approach aims to systematically dimension production resources while considering alternative scaling options, such as a higher degree of automation. By doing so, the approach facilitates the demand-oriented deployment of resources during the ramp-up phase, which helps to control and reduce manufacturing costs. The simulation experiments yield scaling paths that indicate the timing and quantity of resources required to meet changing demands. These paths form the basis for subsequent factory planning steps. For instance, the layout can incorporate the necessary space for a future automation solution that will be profitable, enabling faster adaptation to demand changes and securing competitive advantages. This is demonstrated in a use case where the approach was applied to the factory planning of a new production system for a sensor product family

Demand-supply matching through auctioning for the circular economy

The circular economy aims to reduce the consumption of resources and energy by exploiting multiple use-cycles of components and materials. The creation of new circular businesses hinges on efficient alignment between market demands of circular products with the supply of End-of-life components and materials. In this paper, we address the digitization of a matchmaking tool for the circular economy by defining demand-supply matching (DSM) in context of business link identification and cross-sectorial matchmaking. We further specify a DSM process and p resent our DSM tool, which facilitates publication and search for supplier offerings and demander needs, selection of auctioning candidates, and digitized auctioning and contract definition. By that, this tool supports the alignment of market demands with matching supply offerings. In particular, it combines the steps of publishing, searching, selecting, auctioning and contract definition into one tool, which we argue can make matchmaking more efficient compared to addressing these steps separately. Finally, we present the design of the tool and discuss its merits in light of the needed acceptance for automating business link identification and contractual interactions

Geschichte und Modernisierung der Sozialversicherungswahlen

"Die Soziale Selbstverwaltung ist ein Merkmal des demokratischen Sozialstaats, allerdings auch ein umstrittenes. Das wird vor allem bei den im sechsjährigen Turnus stattfindenden Sozialversicherungswahlen deutlich. Vor der letzten Sozialwahl im Juni 2005 wurde sowohl in der medialen Öffentlichkeit als auch in wissenschaftlichen Fachkreisen massive Kritik an dieser besonderen Verwaltungsform geübt. Es wurde sowohl die Legitimation als auch die Effizienz der Selbstverwaltung in Frage gestellt. Die öffentliche Diskussion über die Zukunft der sozialen Selbstverwaltung und damit über die Sozialversicherungswahlen bewegt sich zumeist zwischen Abschaffung der Sozialwahl oder einer grundlegenden Reform ihrer Organisation. Es gibt keine fundierte Untersuchung, wie eine alternative Organisation der Sozialversicherung aussehen könnte. Diese Lücke wird mit dem Gutachten, das das BMAS im Frühjahr 2007 in Auftrag gegeben hat, gefüllt. Es werden die Geschichte der Sozialversicherungswahlen seit 1953 aufgearbeitet, Reformvorschläge entwickelt und deren Auswirkungen untersucht. Dabei werden verschiedene Reformmodelle untersucht und bewertet: Hierbei werden neben der Klärung der rechtlichen Zulässigkeit der verschiedenen Modelle auch organisatorische, sozialwissenschaftliche und finanzielle Gesichtspunkte als Bewertungskriterien herangezogen. Die Gutachter haben die Ergebnisse ihrer Untersuchungen in einem Empfehlungskatalog zusammengefasst." (Autorenreferat

A Circular Economy Strategy Selection Approach: Component-based Strategy Assignment using the Example of Electric Motors

The sustainability of industrial processes and products is a core issue of our time. There are several approaches to move from a linear, inherently wasteful economic principle to a circular economy focused on conserving products, resources, and energy. However, selecting which of the circular economy strategies ranging from reuse, repurpose, and remanufacture to recycling is crucial to ensure the economic viability of the product. This contribution proposes an iterative, component-based circular economy strategy selection method that supports product and production planners in choosing the appropriate circular economy strategy. For this approach, the suitability of each component for circular economy strategies is assessed based on identified key properties. In case of no fitting strategy, further component decomposition is devised, and the process is repeated. To further support the design of circular economy strategies, a modular process build set is suggested, enabling the swift composition of the processing sequence. The approach is then applied to the example of an electric motor of a battery electric vehicle. The presented approach allows a quick first assessment of the viability of different circular economy strategies and helps product and production engineers develop product-specific circular economy strategies