Publikationen

A data envelopment analysis (DEA) is presented to assess evolutions of firm efficiency and financial performance in automotive supply chains. A sample of 32 decision-making units (DMUs), 17 globally operating original equipment manufacturers (OEMs) and 15 key suppliers from the automotive industry, is in focus of this analysis in which cost levels and capital requirements are put into relation to sales growth and profit. Cost of goods sold, operating capital, and net fixed assets represent the financial input of a company while sales growth and earnings before interest and taxes (EBIT) reflect the financial output. The financial performance of a firm is indicated by its efficiency, calculated by an input-oriented variable returns to scale model. A multiple linear regression analysis reveals which operational performance factors are predictors of financial performance. A longitudinal DEA approach that covers the years from 2003 to 2017 is chosen to reveal performance evolutions over time. In order to analyze the stability of relationships between efficient firms (peers) and inefficient ones (followers) over time, changes in the performance relationship network are assessed in a graph-theoretic approach. In this study, geographical and structural specifics of DMU groups are taken into account. The study reveals similarities and differences between OEMs and their suppliers regarding the importance of value drivers and detects periods of performance losses and recovery from the global economic crisis.

The study at hand elaborates on potential barriers, prerequisites and optimization potentials for the automation of the twistlock handling process in container terminals. A case analysis enlightens latest automation developments of this essential task in container transport. Eight experts from different organizations in maritime logistics and seaport operations were interviewed in a qualitative multiple-case research design. The interviews were evaluated by qualitative-quantitative content analysis with MAXQDA software. Automated twistlock handling systems are hardly implemented, although they represent the missing link between other container handling technology in the automated container transport. The study reveals that most implementation barriers consist of technological issues, followed by economic and strategic barriers. The study identifies implementation strategies and their key success and shows that safety improvements and cost reductions are major benefits of this automation. An innovation framework for this field of automation is conceptualized as scientific contribution. Practical implications include recommendations for relevant stakeholders in container logistics.

The motivations for clothing companies to implement dedicated certification schemes as sustainability practices has received limited attention in sustainable supply chain management (SSCM) research so far. Therefore, it is important to understand how different rationales for the implementation of certification schemes have developed in the past because they considerably influence the overall success of sustainability management efforts. This paper picks up on this gap and presents the results of an in-depth comparative case study drawing on interviews conducted with five managers of three companies from the clothing sector in 2018 and abductive content analysis. By applying such a qualitative approach, this study explores motivations and benefits as well as elaborates on the implementation of certification schemes in apparel supply chains. It outlines that certification in the clothing sector is driven by strategic factors, marketing considerations, and information considering sustainability aspects. The study also shows that certification schemes may strengthen the marketing and competitive position of clothing companies as well as sustainability awareness in textile and apparel supply chains in general. Finally, a framework conceptualized from the findings of the interviews presents relevant SSCM practices in the clothing industry. Therefore, the present study contributes to theory building in SSCM by confirming and extending previous research on the implementation of certification schemes for sustainability, as well as to practice by examining reasons to apply certification schemes and potential performance outcomes.

The proposed study deals with sustainable supply chain management (SSCM) in the textile and apparel (T&A) industry. We analyze prerequisites and practices of supply chain (SC) sustainability in a multiple case study of the German and Ethiopian T&A industry. Our analysis is based on ten semi-structured interviews conducted with the managers of seven companies in the Ethiopian T&A production and the German fair fashion retail industries. The contribution of expert knowledge helps in identifying SC sustainability prerequisites and practices. The chosen cases of production in Ethiopia and retail in Germany highlight the complexity of T&A SCs while representing both the suppliers’ and retailers’ perspectives, which is rare in the related literature. As a major research contribution, the study adapts a framework for SC sustainability in the chemical industry and transfers it to T&A SCs. Moreover, practitioners from the T&A industry find useful insights into relevant practices and their prerequisites, which helps in improving SC sustainability in this sector. The study reveals that management orientation and interest groups such as customers represent the most important prerequisites for sustainability. Manufacturers rely more on internal practices such as monitoring, while retailers focus on external sustainability practices, such as supplier development. In a comparative approach, similarities and differences between T&A SCs and the chemical industry are identified.

Within assembly network supply chains, supply disruptions can occur on every supplier-buyer link. Managing this network unreliability can help to reduce schedule instability and increases the overall efficiency of the supply chain accordingly. In this line, a stylised assembly network supply chain model is proposed with two suppliers and a single buyer using the joint economic lot sizing approach. This supply network can be disrupted by a shortage occurring at one of the two suppliers due to random machine breakdowns, which consequently creates dependent requirements variations affecting both the buyer and the entire network. First, the basic joint economic lot sizing model is extended by the said schedule instability. Second, a solution approach is presented concerning the determination of optimal lot sizes, the investment into the reliability of the supply network as well as the determination of safety stocks. Furthermore, the sensitivity of relevant model parameters is investigated by means of a numerical example. Managerial implications are accordingly derived focusing on the reliability of the supply network members and internal incentive structures.

Dynamic capabilities (DCs) are crucial for companies to attain competitive advantage in dynamic business environments and supply chains, where environmental and social aspects are considered by sustainable supply chain management (SSCM). However, the effects of stakeholder influences on SSCM performance, which results from the interplay of DCs and SSCM practices, need to be analyzed. Therefore, a system dynamics (SD) model is proposed to include the influences of governmental, shareholder, and other external stakeholder pressure. The system behavior, i.e., the company’s SSCM performance, can thus be analyzed in face of varying time delays of stakeholder influences. Findings indicate that different intensities of stakeholder influences affect the development of SSCM practices and DCs of a focal company, and thus, overall SSCM performance. Consequently, intensities of stakeholder influences should be managed accordingly, while the impact of time delays has to be understood to control SSCM performance. The insights gained from the model support the decision- and policy-making, which can be considered from the perspective of the focal company, the regulatory authorities, the shareholders, and other external stakeholders that ultimately translate into customer pressure.

In today’s business, it is largely acknowledged that sustainability has to be considered in managerial decision making and corporate strategy development. However, many firms still face substantial operational and organizational challenges when striving for a transformation toward sustainability, especially when expanding their efforts toward their supplier base. Framed by the recently emerging theoretical lens of the practice-based view and its extension toward the supply chain practice view, and grounded in recent conceptualizations of sustainable supply chain management, the study at hand elaborates on management practices by which firms can improve the sustainability of their supply chains. Due to its high economic relevance and its exposure to increasing sustainability requirements, the chemical process industry is chosen as the empirical research field. Qualitative case study research identifies intra- and inter-organizational practices that are important to achieve and improve supply chain sustainability. A framework that conceptualizes sustainability practices and their implementation prerequisites and performance impacts is derived from interviews with key informants from German chemical manufacturers. This paper contributes to the state-of-the-art of sustainability diffusion in particular through its distinct focus on imitable practices that are easily transferable between companies and hence may help in transforming entire industry sectors toward sustainability.

Sustainable operations and sustainable supply chain management (SSCM) have become a highly relevant topic for scientific research and management, as well as policy-making practice. Despite surging growth in extant research, the need for theoretical and conceptual substantiation persists, and large opportunities for further research remain unexploited. This paper responds to the need for a conceptual foundation and, therefore, aims at providing a structured agenda for future research areas in SSCM. Based on an abductive reasoning approach, SSCM constructs and concepts are gathered from existing literature and recombined into a comprehensive conceptual SSCM framework. Areas and directions for future SSCM research, as suggested in earlier studies, are summarized, positioned in the framework, and outlined to stimulate further SSCM research activities. To overcome the lack of holistic research in the field, sophisticated techniques and integrated systems to support decision-making are required to tackle related issues’ complexity. Therefore, this paper’s contribution lies in the synthesis of state-of-the-art literature to provide a more comprehensive view of SSCM. Researchers may find promising recommendations and a suitable foundation for future studies, while practitioners may find helpful orientation and guidance for decision- and policy-making.

Globalized economic systems involve complex supply chains (SCs) where environmental and social impacts are to be managed in alignment with diverse stakeholder expectations and to mitigate sustainability-related risks. Quantitative modeling approaches for sustainable supply chain management (SSCM) have gained increasing attention. Compared to analytical models and mathematical programming, simulation methods in SSCM are underrepresented, although system dynamics (SD) modeling is suitable to simulate and examine complex and dynamic systems and to support long-term, strategic decision-making. This paper provides a review of SSCM-related SD models, systematizes SSCM from a systems thinking perspective in a conceptual framework, and proposes guidelines for SD modeling in SSCM research. A content analysis of related literature examines SD models for forward, reverse, and closed-loop SCs that include environmental or social aspects of sustainability. It is found that a majority of models deals with macroscopic levels of analysis while models for intra- and inter-organizational SCs are less prominent. SSCM-related SD models integrate environmental and social sustainability metrics, governmental pressures and incentives or customer expectations, but uncertainties and risks are seldom modeled. Inferences for future SD modeling in SSCM are derived from this review to address strengths and shortcomings of extant SD modeling approaches for SSCM. SSCM-related constructs, model validation and the need of hybrid models, which integrate different simulation, optimization, or multi-criteria decision-making models, are addressed. A framework for a systems thinking perspective on SSCM is conceptualized that may serve as a basis for future research.