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Off-site construction (OSC) is an innovative and sustainable construction method. One of its critical success factors is the proper management of its supply chain (SC). Recently, significant research attention has been focused on the modelling of OSC-SC to improve its performance and sustainability. However, the literature still lacks a comprehensive review of the modelling studies on off-site construction -supply chain management (OSC-SCM). Therefore, this research contributes by providing a comprehensive and up-to-date mapping and clustering of 309 journal articles on the modelling of OSC-SC to identify its trends and gaps, and hence, highlight future research opportunities. To achieve these objectives, a mixed review method, consisting of scientometric and systematic reviews, is used. The scientometric review identifies the most prolific journals, researchers, co-occurrence network of keywords, and their citation bursts. On the other hand, the systematic review classifies the articles based on OSC type and supply chain (SC) stage. At each SC stage, the articles are further classified based on problem settings and solution methods. The results show that production problems have received the most attention (i.e., by 28% of the included articles), followed by on-site construction (19%), design (13%), and logistics (7%) problems. However, researchers are more inclined to address problems at multiple SC stages (33%) due to the interrelationship between these stages. Besides, the systematic analysis shows that OSC-SC problems have been solved frequently by a variety of solution methods such as optimization (25%), simulation (13%) and building information modelling (BIM) (9.5%). However, researchers tend more to integrate multiple solution methods (35%) to address the complexities of OSC-SC problems. Finally, the included studies are classified based on the three sustainability dimensions. The results show that economic, environmental, and social sustainability dimensions have been considered in previous studies by 72%, 24%, and 4%, respectively. Therefore, the study identifies research gaps at each SC stage of each OSC type to incentivize future studies to consider more environmental and social sustainability factors in OSC-SC models. Since modular integrated construction (MiC) has the highest prefabrication level, this study provides future research directions for sustainable supply chain management (SCM) in MiC. The present research is an important reference guide that helps researchers and practitioners to understand different problem settings and their solution methods in OSC-SCM.

Collaborative Decision Support Systems (CDSSs) have been increasingly used to organize collaborative transport networks to develop sustainable freight transport. CDSSs involve two main components: a collaborative planning algorithm for matching transport orders to trucking capacities and an interactive front-end (e.g., websites and Email systems) for dispatching freight matches and communication among collaborators. The literature has mostly focused on developing and testing advanced algorithms using historical data. However, these studies test only one component and ignore the front-end that greatly affects the CDSS performance in daily practice. Overall, the literature lacks studies that evaluate and improve the CDSSs based on the feedback of end-users with a pilot test. Though poor data availability and quality are well-known issues in the logistics industry, no previous studies have discussed how to deal with the data issues in the real applications of CDSSs. To bridge these gaps, this study reports our experiences with testing an early version of a CDSS for automated freight matching in Denmark. The test results revealed some issues related to the ease of the CDSS usage and validity of the identified matches. A methodology is proposed to analyze the test results and to inspire ideas for improvement. The analyses showed that low data quality (e.g., missing values) is a significant barrier to developing effective front-end and valid matching. Due to the low data quality, automated matching can be more effective if carriers set their matching preferences through access to the CDSS. Besides, the front-end Email system should be developed in a way that reduces the number of emails, enables snap judgment, and visualizes the match details. Finally, some improvement suggestions are proposed and evaluated.

This study provides explicit mathematical formulations for the bistatic scattering coefficient from a randomly rough surface with a complex relative permittivity based on the following analytic models: small perturbation model (SPM), physical optics model (PO), and Kirchhoff approximation model (KA). Then it addresses the two shortcomings associated with each of the three models: i) limited applicability domain, and ii) null predicted values for the cross polarized bistatic scattering coefficients within plane of incidence. The plane of incidence contains both backscattering direction and forward (specular reflection) direction which are of interest to the spectrum community.

Despite the negative consequences on society and environment, urban freight transport is critical for the prosperity of cities. Decision makers have considered the horizontal collaboration between carriers as a solution to reduce the total transportation cost and the related negative impacts. In literature, the collaborative freight delivery is modelled as a Multi-Depot Vehicle Routing Problem (MDVRP) that can be solved by being decomposed into two sub-problems, i.e. assignment problem and a set of vehicle routing problems. The assignment problem allocates customers to the nearest depots while vehicle routing problem determines the optimal routes to serve customers assigned to each depot. However, most of existing approaches did not consider the interrelation between these two sub-problems, which in turn impairs the solution quality of the overall problem. This paper presents an improved two-level mathematical modelling approach to evaluate and optimize the implementation of the collaborative freight distribution in urban areas. Unlike existing studies, the proposed approach considers the interrelation among the two-sub problems. A real-life case is used to illustrate the savings obtained from the collaborative distribution. In addition, the significance of the proposed approach is demonstrated by a comparison against a similar approach found in literature.

In the recent years, Horizontal Collaboration(HC) has gained an increasing attention in literature as anefficient practice for sustainable freight transportation.However, successful applications of HC in freighttransportation, are rarely reported. This paper contributes toliterature by a Decision-Making Trial and EvaluationLaboratory (DEMATEL)-based approach to develop a betterunderstanding of the main barriers to the implementation ofcollaborative freight transportation in practice. A set of barriersis identified by an extensive literature review, and is groupedinto six categories, i.e. “Design of the collaboration process”,“Information sharing and collection”, “ Partners’ behaviors andtheir relationships”, “Decision making algorithm”, “Web-basedinformation system”, and “Market structure and regulatinglaws”. Then, the DEMATEL method is used to develop causalityand prominence relations among these categories. Finally, thecontributions of barrier categories to the success of thecollaboration process and interrelationships among them aredetermined. The results of this work can provide guidelines todecision makers to address those critical barriers for makingcollaborative logistics practices a success.

Cities across Europe face significant challenges in relation to urban freight transport. The economic development in recent years have boosted activities in the city centres demanding increased freight transport. At the same time, urbanization has increased congestion issues and initiatives to minimize traffic in city centres have made city centres less accessible for freight transport vehicles.A number of studies have explored how to optimize freight transport and minimize the negative externalities through collaborative logistics, a concept which has received a lot of attention in recent years. Collaborative logistics can be either a vertical collaboration between actors of the same supply chain, or a horizontal collaboration between direct competitors, for example competing logistics companies, aiming to decrease the costs of transportation and increase fleet utilization by sharing assets, information, knowledge etc.The idea is built around an example if two competing logistics companies each have half a truckload of goods on the same route, then it makes sense for the companies to share the transport, place the goods on one full vehicle and share the saved costs. In turn, this will also generate environmental benefits, i.e. minimize driving and thus emissions of greenhouse gas, particles and noise.This study provides an overview of the concept of collaborative logistics, and employs mathematical modelling to quantify the benefits which can be gained from collaborative logistics in urban freight delivery and interview-based methods to identify the challenges of implementing collaborative logistics in this setting in practice.The study shows that horizontal collaborative logistics, i.e. collaboration between competing logistics companies, is found the most suitable approach to optimize logistics within given case of Aalborg. Within horizontal logistics two approaches are found, capacity sharing and order sharing. The study shows, that order sharing is the most beneficial approach. Using real-life data from two competing logistics companies, the analysis reveals that collaborative delivery and order sharing can reduce the total travelled distance of each company by an average of 24.75% compared to the non-collaborative distribution. Importantly, the analysis also reveals that even if the participating competitors only choose to share a subset of their orders, a significant reduction in travelled distance and emission is still achievable.The analysis of the barriers shows that accessibility limitations in the city, partner selection issues, loss of a competitive advantage, issues in profit and cost sharing, different delivery structures and uncertainty regarding the branding of the delivery were the main barriers. The analysis also revealed that there is a support for collaboration among relevant stakeholders, however, the stakeholders have a low awareness of potential benefits of collaboration.By simulating and proving the potential benefits of collaborative logistics based on real data, and simultaneously identifying the barriers, one of which being limited knowledge about potential benefits of collaboration, this report constitutes an important step towards implementation of collaborative in cities such as Aalborg.