Journal Articles (Peer-Reviewed)
Ottemöller, Ole and Hanno Friedrich (In press):Opportunities of sectoral freight transport demand modelling, Case Studies on Transport Policy.
Abstract: Abstract This paper discusses the opportunities of sectoral freight transport demand models. The work is based on literature and insights from interdisciplinary research in the field of production, logistics and transport. First, current and future factors influencing freight transport are discussed. Next, a brief summary of the traditional transport modelling approach and recent extensions and adaptations of freight transport models is given. As interdisciplinary research has shown, the impact of the identified factors on the development of freight transport is strongly dependent on the sector under investigation. As a consequence, this paper proposes the application of a sectoral modelling approach. The automotive and food sectors in Germany are used as examples to further examine the opportunities of sectoral freight transport demand models.
Friedrich, Hanno and Jonathan Gumpp (2014):Simplified Modeling and Solving of Logistics Optimization Problems, International Journal of Transportation, 2(1): 33-52.
Abstract: Logistics optimization problems are often complex (NP - hard). Especially for large problem scopes in logistics and new agent-based freight transport models which have to solve these problems for many agents, simplifying modelling and solving procedures are necessary in order to reduce the level of complexity. Due to the variety of existing approaches and the specifics of each problem it is often difficult to find an appropriate method. This paper seeks to facilitate this process as it identifies ‘meta’ heuristics within literature, i.e. abstract courses of action that, when adapted, have proven successful in various problems. It presents a classification of general simplification principles that are useful for reducing the complexity of logistics problems, in order to facilitate understanding between academics and practice. The derivation of the related principles is based on the examination of five problems in logistics literature: facility location, distribution system, lot size, bin packing, and vehicle routing.
Liedtke, Gernot and Hanno Friedrich (2012):Generation of logistics networks in freight transportation models, Transportation, 39(6): 1335-1351.
Abstract: This article analyzes the concept of logistics networks in the context of behavioral freight transport modeling. Starting from the basic definition of networks, the different perceptions of networks in transportation science and logistics are worked out. The micro‐macro gap, as a main challenge in freight transport modeling, is explained by the existence of logistics networks on a meso level. A taxonomy of modeling methods dealing with logistics networks is defined, based on two characteristics: the changeability of networks within models (fixed, partially variable and variable networks) and the form of cost functions mapped (economies of scale, constant average cost, and diseconomies of scale). For each category, different possible modeling methods and their application in existing freight transport models are discussed. A special focus is placed on methodologies and models that map variable networks.
Hansen, Ole and Hanno Friedrich (2014): Approach for Modelling Food Product Inventory Levels - An Analysis of National Food Product Supply Chains, in: Gammelgaard, Britta et al (ed.): 26th Conference of the Nordic Logistics Research Network : NOFOMA 2014, Copenhagen, Denmark: June 11-13, 2014.
Balster, Andreas and Hanno Friedrich (2014): Modelling Dynamic Commodity Flows Using the Example of the German Food Supply Sector, in: Gammelgaard, Britta et al (ed.): 26th Conference of the Nordic Logistics Research Network : NOFOMA 2014, Copenhagen, Denmark: June 11-13, 2014.
Motzke, Andreas, Balster Andreas, Ole Hansen, Maja Herrmannsdörfer, Frank Schätter, Hanno Friedrich, Wolfgang Raskob, Markus Wiens and Frank Schultmann (2014): The SEAK Project: Decision Support for Managing Disruptions in Food Supply Chains, in: Thoma, Klaus (ed.): Future Security - 9th Security Research Conference, Berlin, September 16 - 18, 2014, Fraunhofer-Verl: Stuttgart, 581-584.
Hansen, Ole and Hanno Friedrich (2015): An Inventory-Focused Analysis of German Food Supply Chains: The Case of Dairy Products, in: Clausen, Uwe, Hanno Friech and Christiane Geiger (ed.): Commercial transport - Proceedings of the 2nd Interdiciplinary Conference on Production, Logistics and Traffic 2015, Springer: Cham, Switzerland, 337-347.
Abstract: This work was created as part of the research project SEAK, which looks into possible causes and consequences of food shortfalls in Germany and is moreover also aimed at developing and evaluating possible mitigation strategies for these shortfalls. For the management of shortfalls in food supply it would be, as a first step, crucial to have information on existing inventories. Making for example decisions on the reallocation of food products into regions affected by disasters is only possible if knowledge about the (regional) availability of food quantities is present in the first place. This could be considered as a necessary transparency. However, in the German food sector, it is hard to get data about the inventories kept by companies like producers, logistic service providers (LSP’s), wholesalers or retailers. This is due to the fact that usually companies are not obliged to publish this information. Moreover, this information is also considered confidential in most companies, since it would give competitors insight into their business model and processes, which are oftentimes the basis for their success. Since information concerning food inventories is not publicly available, it has to be derived in another manner. This work is aimed at providing a scientific basis for the modelling of inventories along food supply chains. More specifically, it does so for the food commodity group of dairy products. We gathered information on all available food products, but limit this particular analysis to dairy products as a showcase of our approach. First, we introduce the data set used for the analysis and the methodology applied to it. In a next step, characteristics of typical German dairy supply chains are described using practical evidence as well as literature findings. The description follows the supply chain’s structure from start to finish, downstream. In the end, concluding remarks are made and possible further research ventures are suggested.
Thaller, Carina, Benjamin Dahmen, Gernot Liedtke and Hanno Friedrich (2015): Freight Transport Demand Modelling – Typology of Characterizing Freight Transport Demand Models, in: Clausen, Uwe, Hanno Friech and Christiane Geiger (ed.): Commercial transport - Proceedings of the 2nd Interdiciplinary Conference on Production, Logistics and Traffic 2015, Springer: Cham, Switzerland, 39-54.
Abstract: Due to the structural heterogeneity of freight transport and its long-term subordinate consideration, there have been low research activities in this field as well as low motivations to integrate this segment into transport demand models for decades. There is also no generally valid framework for freight transport modelling in comparison to passenger transport modelling. Without a common framework, it is difficult to exchange ideas between scientists and to enable an efficient communication and solid agreements between a client and a contractor of a transport modelling service. This contribution presents a typological order of characteristics of freight transport demand models which covers their internal structures and employed methods. In addition, a systematic overview of selected international freight transport demand models is given.
Gabler, Manuel, Stefan Schröder, Hanno Friedrich and Gernot Liedtke (2013): Generierung der Nachfragestrukturen für die mikroskopische Simulation des städtischen Distributionsverkehrs im Lebensmittelhandel, in: Clausen, Uwe (ed.): Wirtschaftsverkehr 2013, Springer: Berlin, Heidelberg, 32-48.
Abstract: Wirtschaftsverkehrs- und City-Logistik-Modelle ermöglichen die Simulation des Verkehrsverhaltens sowie die Untersuchung und Bewertung von verschiedenen verkehrspolitischen Maßnahmen. Prominente Maßnahmen sind beispielsweise Einfahrverbote bestimmter Lkw-Typen, räumlich und zeitlich differenzierte Mautgebühren oder die Nutzung von Güterverkehrszentren. Diese Arbeit ist eingebettet in einen übergeordneten Ansatz zur mikroskopischen Modellierung des städtischen Distributionsverkehrs im Lebensmitteleinzelhandel. Neben der Verhaltensmodellierung der Entscheidungsträger sowie der physischen Simulation der Fahrzeugbewegungen liegt die große Herausforderung in der Gewinnung der Modelleingangsdaten zur Beschreibung des umfassenden Entscheidungsproblems in der Distributionslogistik. Die Ableitung dieser Daten sowie die Illustration am Beispiel eines Berlin-Szenarios ist Gegenstand des vorliegenden Aufsatzes.
Friedrich, Hanno, Lorant Tavasszy and Igor Davydenko (2013): Distribution Structures, in: Jong, Gerard de (ed.): Modelling freight transport, First edition ed., Elsevier, 65-87.
Abstract: Distribution structures are important elements of the freight transportation system. Goods are routed via warehouses on their way from production to consumption. This chapter discusses drivers behind these structures, logistics decisions connected to distribution structures on the micro level, and possible modeling methodologies on the macro level. The authors show the connection between the micro and the macro level and highlight advantages of the different modeling approaches.