Prof. Dr. Hanno Friedrich

Assistant Professor of Freight Transportation - Modelling and Policy

Publications

Journal Articles (Peer-Reviewed)

Copy reference link   DOI: http://dx.doi.org/10.1016/j.cstp.2015.08.003

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.

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Copy reference link   DOI: 10.14257/ijt.2014.2.1.03

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.

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Copy reference link   DOI: doi:10.1007/s11116-012-9386-9

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.

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Journal Articles (Professional)

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Abstract: Die Modellierung des Wirtschaftsverkehrs gewinnt aufgrund der aktuellen Anforderungen und Fragestellungen zunehmend an Bedeutung. Daher werden in der FGSV parallel zur Entwicklung entsprechender Regelwerke und Empfehlungen für den Personenverkehr auch der aktuelle Stand der Technik zur Modellierung des Wirtschaftsverkehrs beleuchtet sowie Empfehlungen und Hinweise zu seiner Modellierung entwickelt. Zunächst werden dazu die Fragestellungen analysiert. Im Anschluss daran werden die Unterschiede in der Modellierung des Wirtschaftsverkehrs zum Personenverkehr erläutert. Dabei werden der Modellaufbau, die verwendeten Modellierungsmethoden sowie eine Auswahl von Softwarewerkzeugen vorgestellt und analysiert. Nachdem die wesentlichen Datenquellen für Wirtschaftsverkehrsmodelle benannt wurden, werden abschließend einige Beispiele für Wirtschaftsverkehrsmodelle dargestellt. Due to increasing requirements the modelling of commercial traffic receives more and more attention. The German Road and Transportation Research Association (FGSV) compiled the state-of-practice of modelling transport and included, thus, specific recommendations for commercial transport. This article provides an overview of commercial transport modelling issues: First, the different purposes of modelling commercial transport are listed. In the next step the difference between private and commercial transport modelling is discussed. This section is subdivided into model architecture and modelling methods. An overview of software products is enclosed as well as a description of the relevant input data. The article closes with some examples for commercial transport models.

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Books

Conference Proceedings

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Abstract: ObjectivesThe significance of Logistics Service Providers (LSPs) has risen steadily during the last decades due to trends like logistics outsourcing or the structural change in the types of goods transported. From the freight transport modeller's point of view, integrating LSPs into freight transport models is essential to be capable of describing possible future developments. Especially important is the knowledge of the spatial distribution patterns of LSP locations e.g. to represent network routing of mixed cargo shipments more accurately. Moreover, attributes characterizing the LSP locations are helpful to relate them to traffic generation. Therefore, the objective of this paper is to present intermediate results of empirical work on LSP locations in Germany and their multiple attributes. Drawing on these findings we generate LTL freight for Germany.Data and methodologyFirstly, to identify spatial patterns of LSP locations, a secondary data analysis on the German LSP´s sites was conducted. Data on LSPs and their logistics locations including attributes like geolocation, employment, operations area, infrastructure access, or market segments served was collected. The resulting database was further combined with publicly accessible data e.g. to compute distances to highways. In this paper, the results of statistical analyses on the sample are presented. The sample´s representativeness and completeness of the database are discussed as well. Secondly we generate the LTL freight of LSPs based on generation rates and the location database. The model results are verified in two different ways.Expected resultsThe findings of this paper shed some light on the locations of the German LSP sector and the freight transport it generates. These insights especially include spatial configuration and are highly relevant for freight transport and land use planning policies. In addition, we show a new freight demand generation model based on data of logistics locations or, if we find a way to generate them synthetically, based on more available statistical data.

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Abstract: Due to strong interdependencies between production, logistics and traffic, a decision in one of these fields has impacts on the others. However, decision makers in and around today’s supply chains rarely consider effects of their decisions on other participants of the supply chain or the traffic system. Thus, a tool for decision support, which clearly illustrates the variety of impacts of a decision, is highly desirable. Accordingly, this paper presents a reference model in the context of production, logistics and traffic, called Interdisciplinary Decision Map (IDM). The IDM allows for describing and analyzing interdisciplinary impacts of decisions across the disciplines. Thus, it can serve as decision support tool for decision makers out of the considered domains. The IDM’s applicability is demonstrated by using it to analyze selected impacts of an heavy goods vehicles (HGV) toll’s introduction on production, logistics and traffic.

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Abstract: In this article, basic characteristics of HGV toll systems are described. Based on that, these systems' impacts on entrepreneurial processes and resulting changes in business choices are discussed. Furthermore, a case study on hauliers' reactions on the German HGV toll is presented. The results show that the haulage industry only has to deal with marginal impacts since costs are usually passed along to the customer, this is why operational changes do not seem necessary.

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Abstract: Desicion-makers in and around today's supply chains are facing tough every day. However, when making decisions, they rarely consider what effects their desicions cause upon other participants of the supply chain or traffic management. This is mostly due to the lack of appropriate tools which help indicating the possible effects. Such tools are necessary to tackle the inherent complexity of the whole supply chain system. This paper describes how to construct and design such a tool for this interdisciplinary environment, called an Interdisciplinary Decision Map (IDM). The IDM is a powerful tool to visualise complex relationships, while at the same time retaining usability by showing relevant information only. We show how tu use a specific instance of an IDM to facilitate a better understanding to the underlying processes of other supply chain participants. The soundness of our approach is backed by findings from an interdisciplinary research project.

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Abstract: Supplies of food and water are essential in disaster management, particularly in the very early chaotic phases when demand and available resources are highly uncertain, information systems are disrupted, and communication between communities, food suppliers, retail and emergency authorities is difficult. As many actors and organisations are involved in ever more complex food supply chains, cooperation and collaboration are vital for efficient and effective disaster management. To support decision-makers facing these problems, this paper introduces a scenario-based approach that integrates simulation of disruptions in food supply chains, and qualitative expert assessment to develop consistent scenarios that show the consequences of different strategies. To choose the best individual measures for all relevant actors and to compare it with the best overall strategy approaches from multi-criteria decision analysis are used.

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Abstract: This paper estimates the shippers‟ reactions and their economic benefits from a multimodal transport network called LOGOTAKT. For this purpose, an econometric shipper model is being estimated in which the major factor influencing logistics decisions – the balance between warehouse and storage cost – is explicitly taken into account. The functional form is being deduced from the first order condition of Total Logistics Cost function minimization. Transport cost is expressed in form of a complex function depending on order size and the transport distance in order capture the effect of economies of scale in transportation. It is estimated based on empirical data of distribution obtained from two major German companies. Simulations show that the new multimodal transportation system has a significant impact on shipment size distributions changing them in favor of smaller shipments. This leads especially to significant reductions in warehouse costs. Finally, some implications of the analytical results on transport policy are provided: To achieve further modal shift from road to rail, public financial support and the regulatory framework must put railways into the position to consolidate shipments and to exhaust economies of scale.

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Abstract: This work aims to discuss modeling issues on solving the transport distribution problem in freight transport. The traditional distribution model – the Gravity Model – is introduced in detail with the focus on its forecasting capability of freight transport distribution. Through analyses on the base of observed and predicted data of freight transport in Germany, it is found that, compared to applying the Gravity Model, directly balancing the observed distribution from the last period using the Furness Method can generate more closer predictions to the official predictions in a planning project of the German Federal Ministry of Transport, Building and Urban Development. However, the re is a doubt about whether this Furness Method itself brings about an impact on the deterrence exponent. Based on the proposition that the Furness Method dilutes the deterrence effect of transport costs, a compensating procedure is developed in this work as a supplement to the traditional process, offering a new thinking to improve the prediction performance of distribution models.

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Book Chapters

Copy reference link   DOI: doi:10.1007/978-3-319-41097-5_3

Abstract: Due to strong interdependencies between production, logistics and traffic, a decision in one of these fields has impacts on the others. However, decision-makers in and around today’s supply chains rarely consider effects of their decisions on other participants of the supply chain or the traffic system. Thus, a tool for decision support, which clearly illustrates the variety of impacts of a decision, is highly desirable. Accordingly, this chapter presents a reference model in the context of production, logistics and traffic, called Interdisciplinary Decision Map (IDM). The IDM allows for describing and analysing interdisciplinary impacts of decisions across the disciplines. Thus, it can serve as decision support tool for decision-makers out of the considered domains. The IDM’s applicability is demonstrated by using it to analyse selected impacts of an HGV toll’s introduction on production, logistics and traffic.

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Copy reference link   DOI: 10.1007/978-3-319-21266-1_22

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.

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Copy reference link   DOI: 10.1007/978-3-319-21266-1_3

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.

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Copy reference link   DOI: doi:http://dx.doi.org/10.1016/B978-0-12-410400-6.00004-5

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.

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Copy reference link   DOI: doi:10.1007/978-3-642-37601-6_3

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.

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