TY - JOUR A1 - Kellner, Florian A1 - Lienland, Bernhard A1 - Utz, Sebastian T1 - An a posteriori decision support methodology for solving the multi-criteria supplier selection problem JF - European Journal of Operational Research N2 - This research presents a novel, state-of-the-art methodology for solving a multi-criteria supplier selection problem considering risk and sustainability. It combines multi-objective optimization with the analytic network process to take into account sustainability requirements of a supplier portfolio configuration. To integrate ‘risk’ into the supplier selection problem, we develop a multi-objective optimization model based on the investment portfolio theory introduced by Markowitz. The proposed model is a non-standard portfolio selection problem with four objectives: (1) minimizing the purchasing costs, (2) selecting the supplier portfolio with the highest logistics service, (3) minimizing the supply risk, and (4) ordering as much as possible from those suppliers with outstanding sustainability performance. The optimization model, which has three linear and one quadratic objective function, is solved by an algorithm that analytically computes a set of efficient solutions and provides graphical decision support through a visualization of the complete and exactly-computed Pareto front (a posteriori approach). The possibility of computing all Pareto-optimal supplier portfolios is beneficial for decision makers as they can compare all optimal solutions at once, identify the trade-offs between the criteria, and study how the different objectives of supplier portfolio configuration may be balanced to finally choose the composition that satisfies the purchasing company's strategy best. The approach has been applied to a real-world supplier portfolio configuration case to demonstrate its applicability and to analyze how the consideration of sustainability requirements may affect the traditional supplier selection and purchasing goals in a real-life setting. Y1 - 2019 U6 - https://doi.org/10.1016/j.ejor.2018.06.044 VL - 272 IS - 2 SP - 505 EP - 522 PB - Springer ER - TY - JOUR A1 - Igl, Johannes A1 - Kellner, Florian T1 - Exploring greenhouse gas reduction opportunities for retailers in Fast Moving Consumer Goods distribution networks JF - Transportation Research Part D: Transport and Environment N2 - This research explores logistics-related leverages in the responsibility of retailers for improving the environmental performance of a Fast Moving Consumer Goods (FMCG) distribution network. We examine opportunities for modifying the network carbon footprint by changing network design variables. To do so, a quantitative distribution network model is established, and 150 scenarios are calculated by modifying real-world shipment data from an existing multinational FMCG manufacturer. Four distribution variables are identified for a many-to-many and a hub-and-spoke network structure. Two variables affect the distribution network and two interfere in the shipment structure by manipulating weight and/or the delivery date. This research sheds light on the extent of the changes in greenhouse gas (GHG) emissions of the distribution network that result from modifications in the logistics variables. The greatest effect on the quantity of GHG emissions can be observed when an anticipation horizon for orders is introduced. When shipments are consolidated and delivered only weekly or biweekly from the manufacturer to the retailers, GHG emissions drop significantly. Another opportunity for retailers to cut down GHG emissions is based on the concept of minimum order quantities where shipments to a retailer location are bundled until a certain weight is reached. Additionally, total GHG emissions of distribution may be reduced by raising the tonnage limit, thereby triggering direct shipments between the manufacturer’s facilities and the retailer locations, or by raising the tonnage limit, which triggers direct shipments in the logistics service provider network. The extent of GHG reduction is assessed for all investigated variables. Y1 - 2017 U6 - https://doi.org/10.1016/j.trd.2016.10.008 VL - 50 SP - 55 EP - 69 PB - Elsevier ER - TY - JOUR A1 - Kellner, Florian A1 - Igl, Johannes T1 - Estimating the effect of changing retailing structures on the greenhouse gas performance of FMCG distribution networks JF - Logistics Research N2 - The assessment of greenhouse gas (GHG) emissions of supply chain activities is performed to create transparency across the supply chain and to identify emission-cutting opportunities. Literature provides several generic and case study approaches to estimate GHG emissions. But research often focuses on products. This paper sheds light on how the greenhouse performance of a fast-moving consumer goods (FMCG) distribution network depends on several (FMCG specific) variables to set up a “CO2 network footprint”. Within a quantitative computational study, the distribution network footprint of an existing FMCG manufacturer is analyzed. Three options being fundamentally able to reduce total GHG emissions are identified: number of distribution centers, performance of the engaged logistics service provider and shipment structure. First, transportation processes for the investigated FMCG manufacturer are analyzed to derive GHG emissions caused by different distribution shipments. Second, initial data are manipulated to simulate variable changes, that is, different logistics structures. Third, results are reported and analyzed to show up how different changes in logistics structures may reduce GHG, without technological propulsion or use of regenerative energy. Y1 - 2012 U6 - https://doi.org/10.1007/s12159-012-0063-3 VL - 4 IS - 3-4 SP - 87 EP - 99 PB - Springer Nature ER - TY - JOUR A1 - Kellner, Florian T1 - Exploring the impact of traffic congestion on CO2 emissions in freight distribution networks JF - Logistics Research N2 - This research quantifies the impact that regular road traffic congestion has on the CO2 emissions of a real-world distribution network, and it studies the consequences when the number of distribution centers changes. For this purpose, this study makes use of a network model allowing for a detailed representation of all relevant transport operations, including production flows between factories and distribution centers, line haul shipments between distribution centers and customers, and round/delivery trips between transshipment points and retailer locations for the last mile. The processed trip and traffic information does not rely on standard traffic data collection approaches, such as interviews, in situ technologies, or floating car data, but the road traffic data are retrieved from an online navigation service, such as Bing Maps, Google Maps, Inrix, Here, and TomTom. This study proves that online navigation services may considerably contribute to future research projects analyzing CO2 sensitivities and greenhouse gas cutting opportunities in logistics networks. Y1 - 2016 U6 - https://doi.org/10.1007/s12159-016-0148-5 VL - 9 PB - Springer Nature ER - TY - JOUR A1 - Kraft, Sarah Katharina A1 - Quayson, Matthew A1 - Kellner, Florian T1 - Assessing the German Act on Corporate Due Diligence Obligations in Supply Chains: a perspective from the smallholder cocoa farmer JF - Frontiers in Sustainability N2 - This research examines the potential outputs, outcomes, and impacts of the German Act on Corporate Due Diligence Obligations in Supply Chains (LkSG) on the smallholder cocoa farmers in West Africa. The study primarily relies on a literature review and an impact pathway to conduct a systematic analysis to identify the potential effects of the LkSG on smallholder cocoa farmers. The findings indicate that some, but not all of the risks addressed by the LkSG align with those faced by smallholder cocoa farmers and their families. Additionally, the research also reveals weaknesses, particularly in managing environmental risks, which the LkSG does not adequately cover. Our findings show that in the short- and medium-term, the LkSG has no potential effects on smallholder cocoa farmers. Furthermore, the potential positive impacts of the law on smallholder cocoa farmers will take a long time to realize, as the LkSG considers primarily tier-1 suppliers. Companies in Germany might reassess their supply chains to strive for an LkSG-risk-free supply chain, which could in the long term have sustained impacts on smallholder cocoa farmers. However, we recommend a comprehensive risk analysis of the cocoa supply chain to enhance the human rights of cocoa farmers. Y1 - 2024 U6 - https://doi.org/10.3389/frsus.2024.1376619 VL - 5 PB - frontiers ER - TY - CHAP A1 - Kellner, Florian A1 - Schroder, Nadine T1 - Location Planning & Analysis Using Uncertain Data T2 - 2021 International Conference on Decision Aid Sciences and Application (DASA), 07-08 December 2021, Sakheer, Bahrain N2 - In today's big data era, a humongous amount of data are collected from various sources. In many cases, these data are incomplete, imprecise, and uncertain. An illustrative example is the OpenStreetMap project, where users all over the world contribute data on a more or less precise and complete level. This research shows whether these data are suited to support management decisions. A real-world example demonstrates the extent to which location decisions of a fast-food restaurant chain can be reproduced using techniques from the field of advanced analytics. The problem deals with classifying potential locations and comparing the predicted locations with the actual ones. The data used for this example are retrieved from the OpenStreetMap project. We find that the OpenStreetMap data are generally suitable for predicting location decisions. However, the choice of the data analytics technique is crucial. In our illustrative example case, boosted trees resulted in the best forecast, thereby outperforming neural networks, classic trees, and logit models. Y1 - 2021 SN - 978-1-6654-1634-4 U6 - https://doi.org/10.1109/DASA53625.2021.9682323 SP - 720 EP - 723 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Kraft, Sarah Katharina A1 - Kellner, Florian T1 - Can Blockchain Be a Basis to Ensure Transparency in an Agricultural Supply Chain? JF - Sustainability N2 - Many supply chains within developing countries lack transparency and are fraught with fraud, corruption, and a substantial number of intermediaries. For several decades, the cocoa sector has faced multiple social, economic, and environmental challenges, some of which include the issue of child labor and very low incomes for farmers, leading to poor living conditions. Blockchain technology has a high potential to reduce—or completely eradicate—some of these hurdles. In this article, we present a blockchain-based solution based on the open-source framework Hyperledger Fabric for the cocoa supply chain to promote transparency and reduce fraud. In doing so, we explicitly describe how farmers can be directly integrated into the whole blockchain solution considering the limited infrastructure, knowledge, and technologies available to them. Since about 70% of all cocoa worldwide is produced in West Africa, this case study uses the cocoa sector in Ghana as an example. Y1 - 2022 U6 - https://doi.org/10.3390/su14138044 VL - 14 IS - 13 PB - MDPI ER - TY - JOUR A1 - Kellner, Florian A1 - Otto, Andreas T1 - Allocating CO2 emissions to shipments in road freight transportation JF - Journal of Management Control N2 - Logistic activity, in particular transportation, produces green house gases (GHG). For different purposes GHG need to be allocated to objects. This paper studies how to allocate the GHG volume of a transportation process (delivery tour) to the single shipments moved by the process. First, it identifies classes of generic allocation schemes and presents 15 allocation methods. Second, since the majority of these methods has not been designed for allocating GHG, we apply and compare them in the short distance transport context within a numerical example. The aim is to study how the schemes perform according to criteria. We suggest using causality, efficiency, empty core robustness, symmetry, individual rationality, coalition stability, ease of application, and set robustness as appraisal criteria and attempt to mainstream the discussion by recommending selected allocation methods. Y1 - 2012 U6 - https://doi.org/10.1007/s00187-011-0143-6 VL - 22 IS - 4 SP - 451 EP - 479 PB - Springer ER - TY - CHAP A1 - Lukesch, Maximilian A1 - Kellner, Florian ED - Pradel, Uwe-Heiner T1 - Geoinformationssysteme für Logistikmanager: Eine praxisorientierte Einführung am Beispiel der Freeware QGIS T2 - Praxishandbuch Logistik Y1 - 2019 PB - Wolters Kluwer CY - Köln ER - TY - INPR A1 - Kellner, Florian A1 - Utz, Sebastian T1 - Sustainability in Supplier Selection and Order Allocation: Combining Integer Variables With Markowitz Portfolio Theory T2 - SSRN Electronic Journal N2 - This research presents a decision support methodology for the multi-criteria supplier selection and order allocation problem. The proposed approach supports purchasing managers in assembling mid-term supplier portfolios while making them aware of the trade-offs between the supplier sustainability, the purchasing costs, and the overall supply risk. First, we propose a multi-objective optimization model with three objectives: to maximize the supplier sustainability, to select the supplier portfolio with the lowest purchasing costs, and to minimize the supply risk. Our model extends existing mathematical approaches that follow the portfolio theory fathered by H. Markowitz by integrating the aspect ‘risk’ into the supplier selection problem. Secondly, since we allow for integer variables in our model — in contrast to the classical Markowitz portfolio theory — we use the ε-constraint method to visualize the efficient surface. The possibility of considering the non-dominated set of supplier portfolios is advantageous for purchasing managers as they gain a picture of the different optimal supplier portfolios and are able to analyze the trade-offs between the different purchasing goals before making a decision. Finally, we illustrate the applicability of the proposed methodology in a real-world supplier selection and order allocation case from the automotive industry. In the example case, we identify 1,754 optimal supplier portfolios that may be assembled based on the eight available suppliers. Our analyses show that each optimal portfolio consists of two suppliers, with one specific supplier being included in each portfolio. Furthermore, four suppliers are not part of any optimal solution. Y1 - 2018 U6 - https://doi.org/10.2139/ssrn.3296016 N1 - Erschienen bei Springer im Journal of Cleaner Production 214, 2025: https://doi.org/10.1016/j.jclepro.2018.12.315 PB - SSRN ER - TY - INPR A1 - Kellner, Florian T1 - Generating Greenhouse Gas Cutting Incentives when Allocating Carbon Dioxide Emissions to Shipments in Road Freight Transportation T2 - SSRN Electronic Journal N2 - Road freight transportation accounts for a great share of the anthropogenic greenhouse gas (GHG) emissions. In order to provide a common methodology for carbon accounting related to transport activities, the European Committee for Standardization has published the European Norm EN-16258. Unfortunately, EN-16258 contains in its current version some gaps and ambiguities and leaves room for interpretation, which makes the comparison of the environmental performance of different logistics networks still difficult and hinders the identification of best practices. This research aims to overcome the ambiguities of EN-16258 concerning the allocation of GHG emissions to shipments in road freight transportation. In detail, we apply concepts of the cooperative game theory to identify among all allocation units specified by EN-16258 the most meaningful one. In doing so, we continue previous research projects that analyzed two important aspects of the EN-16258 allocation rules: accuracy and fairness. This study provides further insights into this allocation problem by investigating the incentive power of the different allocation schemes to opt for the GHG minimal way of running a road freight transport network. First, we complement the list of transport scenarios introduced by the prior research projects and present two novel transport scenarios. Second, we carry out a series of numerical experiments to compare the performance of the EN-16258 allocation rules with respect to accuracy, fairness, and the GHG minimizing incentive. Across all aspects, and taking the findings of the prior research projects into account, we conclude that the distance-based allocation rule is the most meaningful one. Y1 - 2020 U6 - https://doi.org/10.2139/ssrn.3518014 N1 - Erschienen bei Springer im OR-Spektrum 44, 2020(3): https://doi.org/10.1007/s00291-022-00675-y ER - TY - JOUR A1 - Kunkler, Jan A1 - Kellner, Florian T1 - Sustainable City Evaluation Using the Database for Estimation of Road Network Performance JF - Sustainability N2 - This article introduces the Database for Estimation of Road Network Performance (DERNP) to enable wide-scale estimation of relevant Road Network Performance (RNP) factors for major German cities. The methodology behind DERNP is based on a randomized route sampling procedure that utilizes the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) in combination with the tile-based HERE Maps Traffic API v7 and a digital elevation model provided by the European Union’s Earth Observation Programme Copernicus to generate a large set of independent and realistic routes throughout OpenStreetMap road networks. By evaluating these routes using the PHEMLight5 framework, a comprehensive list of RNP parameters is estimated and translated into polynomial regression models for general usage. The applicability of these estimations is demonstrated based on a case study of four major German cities. This case study considers network characteristics in terms of detours, infrastructure, traffic congestion, fuel consumption, and CO2 emissions. Our results show that DERNP and its underlying randomized route sampling methodology overcomes major limitations of previous wide-scale RNP approaches, enabling efficient, easy-to-use, and region-specific RNP comparisons. Y1 - 2023 U6 - https://doi.org/10.3390/su15010733 VL - 15 IS - 1 PB - MDPI ER - TY - GEN A1 - Lukesch, Maximilian A1 - Kellner, Florian T1 - Business Analytics and Big Data: Production, Logistics and Supply Chain Management T2 - 1. Regensburger Big Data Day, 30 Oktober 2018, Regensburg N2 - Das Poster befasst sich mit dem Beitrag der Auswertung von "Big Data" für die Anwendungsbereiche der Produktion, der Logistik und des Supply Chain Management. Im Kern steht dabei die Anwendung von Business Analytics Methoden und die Umsetzung der Analytics-Ergebnisse in anwendungsorientierte Use Cases. Als Beispiele werden besprochen: Predictive Maintenance, Supply Chain Monitoring, Supply Chain Risk Management, Demand Forecasting. Y1 - 2018 U6 - https://doi.org/10.5283/epub.37889 ER - TY - BOOK A1 - Kellner, Florian A1 - Brabänder, Christian T1 - VBA mit Excel : Einführung für Betriebswirte N2 - Dieses Buch bietet eine anwendungsorientierte Einführung in die Programmierung mit Visual Basic for Applications (VBA) in Microsoft Excel. Es ermöglicht auch Einsteigern die selbstständige Lösung kleiner bis mittelgroßer Programmieraufgaben aus dem betriebswirtschaftlichen Alltag. Der Schwierigkeitsgrad der Inhalte ist überwiegend einfach gehalten, sodass Nutzer, die bereits grundlegende Tätigkeiten in MS Excel beherrschen, sich nach ihren jeweiligen Anforderungen entsprechend fortbilden können. Zahlreiche Praxisbeispiele und Übungen, die auf einem Windows-Betriebssystem entwickelt und getestet wurden, unterstützen das Lernen Schritt für Schritt und zeigen, wie hilfreich VBA durch Automatisierung und Individualisierung in jedem Büro sein kann. Y1 - 2019 SN - 9783662597408 U6 - https://doi.org/10.1007/978-3-662-59740-8 PB - Springer Gabler CY - Berlin ER - TY - BOOK A1 - Lukesch, Maximilian A1 - Kellner, Florian T1 - Übungsbuch Produktionswirtschaft : Planung, Steuerung und Industrie 4.0 N2 - Dieses Buch bietet Studierenden mehr als 70 Übungsaufgaben und drei Fallstudien inklusive ausführlicher Lösungen zu ausgewählten Themen der Produktionswirtschaft und Industrie 4.0. Jedes Kapitel enthält eine kurze Einleitung sowie zu erreichende Lernziele. Querverweise auf das Lehrbuch „Produktionswirtschaft“ von Kellner/Lienland/Lukesch erleichtern das Selbststudium und ermöglichen eine optimale Prüfungsvorbereitung. In der 2. Auflage wurden umfangreiche Überarbeitungen hinsichtlich Sprache und Aufbau von Aufgaben, Lösungswegen und Abbildungen vorgenommen sowie zahlreiche neue Aufgaben ergänzt. Y1 - 2020 SN - 978-3-662-62086-1 U6 - https://doi.org/10.1007/978-3-662-62087-8 PB - Springer Gabler CY - Berlin ET - 2., überarbeitete und erweiterte Auflage ER - TY - GEN A1 - Kellner, Florian A1 - Utz, Sebastian T1 - Using Inverse Optimization to Discover Sustainability Priorities in Purchasing Decisions T2 - International Conference on Operations Research 2023 // 29. Aug. - 01. Sep. 2023, Hamburg Y1 - 2023 ER - TY - GEN A1 - Kellner, Florian T1 - Multi-objective supplier portfolio configuration under supply risk and sustainability considerations T2 - International Conference on Operations Research (OR2017), September 2017, Berlin Y1 - 2017 ER - TY - CHAP A1 - Kellner, Florian A1 - Otto, Andreas A1 - Busch, Andreas ED - Ivanov, Dimitri ED - Sokolov, Boris ED - Käschel, Joachim T1 - Distribution Networks - Rigid Investments In Dynamic Environments T2 - Flexibility and adaptability of global supply chains - Proceedings of the 7th German-Russian Logistics Workshop (DR-LOG 2012) Y1 - 2012 SP - 103 EP - 111 CY - Sankt Petersburg ER - TY - GEN A1 - Kellner, Florian T1 - Visual decision support for the multi-objective supplier selection problem T2 - International Conference on Multiple Objective Programming and Goal Programming (MOPGP), 30-31 October 2017, Metz, France Y1 - 2017 ER - TY - GEN A1 - Kellner, Florian A1 - Utz, Sebastian T1 - Exploring Sustainability Priorities in Purchasing Decisions Based on Inverse Optimization T2 - NAMA Conference 2023, 28.-29. Sep. 2023, Oldenburg Y1 - 2023 ER -