This paper presents a review of city logistics (also known as urban freight transportation) modelling efforts reported in the literature for urban freight analysis. The review is based on an extensive search of the academic literature. We position the contributions in a framework that takes into account the diversity and complexity found in the present-day city logistics practice. The framework covers the fundamental aspects in the modelling selection process, including: (1) the stakeholders involved in the model, (2) the defining criteria, that is the descriptor for modelling purpose, (3) the objective of the model and (4) the solution approach implemented for achieving the objective. In our discussion and overview, we take these situational factors as the starting point for categorizing and evaluating the city logistics modelling literature. The review analyses the trends of city logistics modelling research in terms of its relevance to city logistics problems and attempts to identify missing links in modelling the urban freight domain.
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Efficiency of city logistics activities suffers due to conflicting personal preferences and distributed decision making by multiple city logistics stakeholders. This is exacerbated by interdependency of city logistics activities, decision making with limited information and stakeholders’ preference for personal objectives over system efficiency. Accordingly, the key to understanding the causes of inefficiency in the city logistics domain is understanding the interaction between heterogeneous stakeholders of the system. With the capabilities of representing a system in a natural and flexible way, agent based modelling (ABM) is a promising alternative for the city logistics domain. This research focuses on developing a framework for the successful implementation of the ABM approach for the city logistics domain. The framework includes various elements – a multi-perspective semantic data model (i.e. ontology) and its validation, the development of an agent base model using this ontology, and a validation approach for the agent-based model. Conclusively, the framework shows that a rigorous course can be taken to successfully implement agent based modelling approach for the city logistics domain.
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Summary Project objectives This study fits into a larger research project on logistics collaboration and outsourcing decisions. The final objective of this larger project is to analyze the logistics collaboration decision in more detail to identify thresholds in these decisions. To reach the overall objectives, the first step is to get a clearer picture on the chemical and logistics service providers industry, sectors of our study, and on logistics collaboration in these sectors. The results of this first phase are presented in this report. Project Approach The study consists of two parts: literature review and five case studies within the chemical industry. The literature covers three topics: logistics collaboration, logistics outsourcing and purchasing of logistics services. The five case studies are used to refine the theoretical findings of the literature review. Conclusions Main observations during the case studies can be summarized as follows: Most analyzed collaborative relationships between shippers and logistics service providers in the chemical industry are still focused on operational execution of logistics activities with a short term horizon. Supply management design and control are often retained by the shippers. Despite the time and cost intensive character of a logistics service buying process, shippers tendering on a very regular basis. The decision to start a new tender project should more often be based on an integral approach that includes all tender related costs. A lower frequency of tendering could create more stability in supply chains. Beside, it will give both, shippers and LSPs, the possibility to improve the quality of the remaining projects. Price is still a dominating decision criterion in selecting a LSP. This is not an issue as long as the comparison of costs is based on an integral approach, and when shippers balance the cost criterion within their total set of criteria for sourcing logistics services. At the shippers' side there is an increased awareness of the need of more solid collaboration with logistics service providers. Nevertheless, in many cases this increased awareness does not actually result in the required actions to establish more intensive collaboration. Over the last years the logistics service providers industry was characterized by low profit margins, strong fragmentation and price competition. Nowadays, the market for LSPs is changing, because of an increasing demand for logistics services. To benefit from this situation a more pro-active role of the service providers is required in building stronger relationships with their customers. They should pay more attention on mid and long term possibilities in a collaborative relation, in stead of only be focused on running the daily operation.
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Western-European consumers have become not only more demanding on product availability in retail outlets but also on other food attributes such as quality, integrity, and safety. When (re)designing food supply-chain networks, from a logistics point of view, one has to consider these demands next to traditional efficiency and responsiveness requirements. The concept ‘quality controlled logistics’ (QCL) hypothesizes that if product quality in each step of the supply chain can be predicted in advance, goods flows can be controlled in a pro-active manner and better chain designs can be established resulting in higher product availability, constant quality, and less product losses. The paper discusses opportunities of using real-time product quality information for improvement of the design and management of ‘AgriFood Supply Chain Networks’, and presents a preliminary diagnostic instrument for assessment of ‘critical quality’ and ‘logistics control’ points in the supply chain network. Results of a tomato-chain case illustrate the added value of the QCL concept for identifying improvement opportunities in the supply chain as to increase both product availability and quality. Future research aims for the further development of the diagnostic instrument and the quantification of costs and benefits of QCL scenarios.
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from the article: "Abstract The way in which construction logistics is organised has considerable impact on production flow, transportation efficiency, greenhouse gas emissions and congestion, particularly in urban areas such as city centres. In cities such as London and Amsterdam municipalities have issued new legislation and stricter conditions for vehicles to be able to access cities and city centres in particular. Considerate clients, public as well private, have started developing tender policies to encourage contractors to reduce the environmental impact of construction projects. This paper reports on an ongoing research project applying and assessing developments in the field of construction logistics in the Netherlands. The cases include contractors and third party logistics providers applying consolidation centres and dedicated software solutions to increase transportation efficiency. The case show various results of JIT logistics management applied to urban construction projects leading to higher transportation efficiencies, and reduced environmental impact and increased production efficiency on site. The data collections included to-site en on-site observations, measurement and interviews. The research has shown considerable reductions of vehicles to deliver goods and to transport workers to site. In addition the research has shown increased production flow and less waste such as inventory, waiting and unnecessary motion on site."
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Urban construction logistics has a big impact on cities. The topic of this paper is governance strategies for realising more sustainable urban construction logistics. Although not much research has been done in the field of governance of construction logistics, several authors have stressed the fragmented nature of the construction industry and the importance of collaboration in urban construction logistics as issues. A literature review was done to identify the barriers in collaboration. Based on these barriers the research objective was to determine which drivers for collaborative governance are needed to improve urban construction logistics. The methods for data collection were semi-structured interviews and a focus group. The collaborative governance model is applied as a strategy to overcome the barriers in collaboration and governance identified. Key findings are both formal and informal barriers hinder the governance of construction logistics. Based on a collaborative governance model we identified four for improving collaborative governance.
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Several studies show that logistics facilities have spread spatially from relatively concentrated clusters in the 1970s to geographically more decentralized patterns away from urban areas. The literature indicates that logistics costs are one of the major influences on changes in distribution structures, or locations and usage of logistics facilities. Quantitative modelling studies that aim to describe or predict these phenomena in relation to logistics costs are lacking, however. This is relevant to design more effective policies concerning spatial development, transport and infrastructure investments as well as for understanding environmental consequences of freight transport. The objective of this paper is to gain an understanding of the responsiveness of spatial logistics patterns to changes in these costs, using a quantitative model that links production and consumption points via distribution centers. The model is estimated to reproduce observed use of logistics facilities as well as related transport flows, for the case of the Netherlands. We apply the model to estimate the impacts of a number of scenarios on the spatial spreading of regional distribution activity, interregional vehicle movements and commodity flows. We estimate new cost elasticities, of the demand for trade and transport together, as well as specifically for the demand for the distribution facility services. The relatively low cost elasticity of transport services and high cost elasticity for the distribution services provide new insights for policy makers, relevant to understand the possible impacts of their policies on land use and freight flows.
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With the approach of the zero emission zone implementation in 30-40 cities mandated by the Dutch Klimaatakkord, comes the need to determine whether the SMEs located within these zones are aware of the coming changes and if they are, how far they have come in their preparation. This paper delves into the development of the zero emission city logistics maturity model tool which is used to indicate the progress of these small to medium enterprises in light of reaching fully zero emission city logistics operations. The paper starts off with a review of existing maturity models which forms the baseline for the zero emission city logistics maturity model in rubric form. A QuickScan analysis is developed in order to facilitate data collection by students who then approach businesses and use the QuickScan results to benchmark the businesses progress against other businesses. This paper then concludes with the preliminary results from the initial QuickScans performed by HBO level students.
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Municipalities play an important role in tackling city logistics related matters, having many instruments at hand. However, it is not self-evident that all municipalities use these instruments to their full potential. A method to measure city logistics performance of municipalities can help in creating awareness and guidance, to ultimately lead to a more sustainable environment for inhabitants and businesses. Subsequently, this research is focused on a maturity model as a tool to assess the maturity level of a municipality for its performance related city logistics process management. Various criteria for measuring city logistics performance are studied and based on that the model is populated through three focus fields (Technical, Social and Corporate, and Policy), branching out into six areas of development: Information and communication technology, urban logistics planning, Stakeholder communication, Public Private Partnerships, Subsidisation and incentivisation, and Regulations. The CL3M model was tested for three municipalities, namely, municipality of Utrecht, Den Bosch and Groningen. Through these maturity assessments it became evident the model required specificity complementary to the existing assessment interview, and thus a SWOT analysis should be added as a conclusion during the maturity assessment.
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Three empirical models were used to fit the formation of acrylamide in crisps of three different cold-sweetened potato genotypes, fried under the same experimental conditions. Statistical methods were used to compare the performance of the models, with the "Logistic-Exponential" model performing the best. The obtained model parameters for the formation of acrylamide showed improvement in precision compared to an earlier study, the precision of the parameter estimates for the degradation of acrylamide was still problematic. Nevertheless, the predictive capacity of the "Logistic-Exponential" model was tested, as this model showed a strong correlation between parameter a and the reducing sugar content of the raw potato. The predictions from this model for the formation of acrylamide in potato crisps were close to earlier reported experimental values. Therefore, the use of the "Logistic-Exponential" model as a tool to predict acrylamide in potato crisps seems promising and should be developed further.
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