European Journal of Transport and Infrastructure Research
Transport and logistics are essential to modern societies including Europe. Not only do they enab... more Transport and logistics are essential to modern societies including Europe. Not only do they enable an unprecedented mobility to individuals, they also offer us a wide variety of products and services affecting our world view and even our portrayal of mankind. The main functions being taken and provided by transport and logistics are geographic and time utility – the former is enhanced by linking scattered locations in a harmonised manner, while the latter is enhanced by offering that what is needed, at the right time. These functions become even more evident as we are now living in an era of globalisation.
European Journal of Transport and Infrastructure Research
A well-structured supply chain is of key importance in achieving efficient operations amongst the... more A well-structured supply chain is of key importance in achieving efficient operations amongst the suppliers, manufacturers, distribution facilities and distribution channels that constitute the supply chain. The changing economic and political environment challenges multinational corporations to redesign their existing production and distribution network and to develop new strategies to meet customer service levels at lowest cost. This paper reviews the literature on supply chain design since 1999 with the objective of supporting the development of richer supply chain models capable of taking all logistics costs into account thereby optimizing the full cost of ownership for multinational corporations and allowing for a consolidation of value adding activities in high-wage regions.
European Journal of Transport and Infrastructure Research
This paper reports on a reverse logistics survey of shippers and logistics service providers in F... more This paper reports on a reverse logistics survey of shippers and logistics service providers in Flanders, one of the leading logistics regions in Europe. We characterise the reverse logistics activities with respect to return reasons, recovery options, outsourcing, lifecycle length and value of products. Practically all the respondents have to deal either with shortlife cycle or low-value products, or both, stressing the importance of efficient reverse logistics handling. Yet, in spite of the increasing attention that reverse logistics is receiving in management literature, its full potential still appears to be under exploited in practice. Respondents consider reverse logistics processes to be out of control, especially for packaging and support materials and still with relatively modest management attention. In addition, we assess the future outlook and potential growth. Almost all companies expect an increase of management attention for reverse logistics, and the results show a l...
The most common approaches to solve the variants of the well-known vehicle routing problem are ba... more The most common approaches to solve the variants of the well-known vehicle routing problem are based on metaheuristic hill-climbing search. The deficiency of these methods is slow local search based hill climbing that often is restricted to limited local neighborhood. In this paper we suggest a novel new two-phase metaheuristic that escapes the local minima with jumps of varying size, instead of step by step local hill climbing. The initial solution is first generated with a powerful ejection pool heuristic. The key idea of the improvement phase is to combine large neighborhood search with standard guided local search metaheuristic in a novel way, allowing improved search diversification and escape from local minima in more efficient way through jumps. The algorithm has been tested on the standard Gehring and Homberger benchmarks for the vehicle routing problem with time windows and the results indicate very competitive performance. We found 12 new and 43 matched best-known solution...
This paper introduces the vehicle routing problem with partial outsourcing (VRPPO) in which a cus... more This paper introduces the vehicle routing problem with partial outsourcing (VRPPO) in which a customer can be served by a single private vehicle, by a common carrier, or by both a single private vehicle and a common carrier. As such, it is a variant of the vehicle routing problem with private fleet and common carrier (VRPPC). The objective of the VRPPO is to minimize fixed and variable costs of the private fleet plus the outsourcing cost. We propose two different path-based formulations for the VRPPO and solve these with a branch-and-price-and-cut solution method. For each path-based formulation, two different pricing procedures are designed and used when solving the linear relaxations by column generation. To assess the quality of the solution methods and gain insight in potential cost improvements compared with the VRPPC, we perform tests on two instance sets with up to 100 customers from the literature.
The team orienteering problem (TOP) aims at finding a set of routes subject to maximum route dura... more The team orienteering problem (TOP) aims at finding a set of routes subject to maximum route duration constraints that maximize the total collected profit from a set of customers. Motivated by a real-life automated teller machine cash replenishment problem that seeks for routes maximizing the number of bank account holders having access to cash withdrawal, we investigate a generalization of the TOP that we call the team orienteering problem with overlaps (TOPO). For this problem, the sum of individual profits may overestimate the real profit. We present exact solution methods based on column generation and a metaheuristic based on large neighborhood search to solve the TOPO. An extensive computational analysis shows that the proposed solution methods can efficiently solve synthetic and real-life TOPO instances. Moreover, the proposed methods are competitive with the best algorithms from the literature for the TOP. In particular, the exact methods can find the optimal solution of 371...
In the vehicle routing problem with multiple time windows (VRPMTW), a single time window must be ... more In the vehicle routing problem with multiple time windows (VRPMTW), a single time window must be selected for each customer from the multiple time windows provided. Compared with classical vehicle routing problems with only a single time window per customer, multiple time windows increase the complexity of the routing problem. To minimize the duration of any given route, we present an exact polynomial time algorithm to efficiently determine the optimal start time for servicing each customer. The proposed algorithm has a reduced worst-case and average complexity than existing exact algorithms. Furthermore, the proposed exact algorithm can be used to efficiently evaluate neighborhood operations during a local search resulting in significant acceleration. To examine the benefits of exact neighborhood evaluations and to solve the VRPMTW, the proposed algorithm is embedded in a simple metaheuristic framework generating numerous new best known solutions at competitive computation times.
The need to reduce pollution and traffic in city centers requires the use of small vans, electric... more The need to reduce pollution and traffic in city centers requires the use of small vans, electric vehicles, and drones to distribute goods. Because of autonomy and capacity issues, these vehicles need to perform multiple trips from/to the depot during the day. The category of decision-making problems modeling such distribution problems are known as multitrip vehicle-routing problems (MTVRPs), which generalize the well-known vehicle-routing problem by allowing vehicles to perform multiple trips per day. Several MTVRPs are solved in the literature with different mathematical models and algorithms. In “An Exact Solution Framework for Multitrip Vehicle-Routing Problems with Time Windows,” R. Paradiso, R. Roberti, D. Laganà, and W. Dullaert propose a single algorithm that can solve, to optimality, the MTVRP with capacity and time windows constraints and four variants of this problem featuring additional operational constraints. The proposed framework significantly outperforms the state-o...
International Journal of Operations & Production Management, 2019
Purpose The purpose of this paper is to develop propositions explaining the influence of individu... more Purpose The purpose of this paper is to develop propositions explaining the influence of individual goals and social preferences on human decision making in transport planning. The aim is to understand which individual goals and social preferences planners pursue and how these influence planners’ decisions. Design/methodology/approach Propositions are developed based on investigation of decision making of transport planners in a Dutch logistics service provider using multiple data collection methods. Findings The study shows how decision making of transport planners is motivated by individual goals as well as social preferences for reciprocity and group identity. Research limitations/implications Further research including transaction data analysis is needed to triangulate findings and to strengthen conclusions. Propositions are developed to be tested in future research. Practical implications Results suggest that efforts to guide planners in their decision making should go beyond t...
The International Journal of Logistics Management, 2019
PurposeThe purpose of this paper is to establish criteria for evaluating strategic partners in a ... more PurposeThe purpose of this paper is to establish criteria for evaluating strategic partners in a network of logistics service providers (LSPs) to show how analytical network process (ANP) can be used to identify the weights of these criteria on a case-specific basis, and to investigate whether the ANP model can be used as a starting point to evaluate strategic partners for other LSP networks.Design/methodology/approachBased on a literature review of vertical cooperation, the authors develop an overview of criteria for the evaluation of partners in a network of LSPs. The authors then apply ANP at LSP1 to validate the criteria, identify weights for these criteria and to validate model outcomes. Furthermore, the authors investigate whether the ANP model developed for LSP1 can be applied to another LSP with similar characteristics (LSP2). In-depth interviews are used to draw conclusions on the modeling approach and the model outcomes.FindingsThe research shows that evaluation criteria f...
The International Journal of Logistics Management, 2018
PurposeThe purpose of this paper is to present a literature review that aims to provide insight i... more PurposeThe purpose of this paper is to present a literature review that aims to provide insight into the characteristics and effectiveness of supply chain visibility (SCV), as well as to identify metrics that capture these aspects in business processes.Design/methodology/approachA systematic review of the supply chain literature is conducted to identify the characteristics and the effectiveness of SCV. The synthesis of SCV effectiveness and its metrics are based on the process-oriented approach which relates the effectiveness of SCV to improved business performance.FindingsThis study reveals that the characteristics of SCV can be captured in terms of the accessibility, quality, and usefulness of information. The benefits of SCV are found to extend beyond improvements to operational efficiency of business processes or to the strategic competencies of an organization.Practical implicationsThis study underlines that clear agreements between all players involved in the SC can help to so...
Supply Chain Management: An International Journal, 2017
Purpose The aim of this paper is to conduct a systematic literature review to understand the stat... more Purpose The aim of this paper is to conduct a systematic literature review to understand the state of the art of partnerships between humanitarian organizations and business corporations in managing humanitarian logistics. Design/methodology/approach A systematic literature review is conducted based on the steps proposed by Denyer and Tranfield (2009). The context-intervention-mechanism-outcome (CIMO) logic is applied to identify the state of the art of partnerships between humanitarian organizations and business corporations in humanitarian logistics. Thirty-six papers related to the topic are extracted from recognized journal databases and then classified into four categories based on the CIMO logic: situational context, intervention factors, mechanisms and outcomes. Findings The study shows that while the context and mechanisms for developing cross-sector partnerships between the humanitarian and the business sector have been examined and illuminated by many researchers, addition...
European Journal of Transport and Infrastructure Research
Transport and logistics are essential to modern societies including Europe. Not only do they enab... more Transport and logistics are essential to modern societies including Europe. Not only do they enable an unprecedented mobility to individuals, they also offer us a wide variety of products and services affecting our world view and even our portrayal of mankind. The main functions being taken and provided by transport and logistics are geographic and time utility – the former is enhanced by linking scattered locations in a harmonised manner, while the latter is enhanced by offering that what is needed, at the right time. These functions become even more evident as we are now living in an era of globalisation.
European Journal of Transport and Infrastructure Research
A well-structured supply chain is of key importance in achieving efficient operations amongst the... more A well-structured supply chain is of key importance in achieving efficient operations amongst the suppliers, manufacturers, distribution facilities and distribution channels that constitute the supply chain. The changing economic and political environment challenges multinational corporations to redesign their existing production and distribution network and to develop new strategies to meet customer service levels at lowest cost. This paper reviews the literature on supply chain design since 1999 with the objective of supporting the development of richer supply chain models capable of taking all logistics costs into account thereby optimizing the full cost of ownership for multinational corporations and allowing for a consolidation of value adding activities in high-wage regions.
European Journal of Transport and Infrastructure Research
This paper reports on a reverse logistics survey of shippers and logistics service providers in F... more This paper reports on a reverse logistics survey of shippers and logistics service providers in Flanders, one of the leading logistics regions in Europe. We characterise the reverse logistics activities with respect to return reasons, recovery options, outsourcing, lifecycle length and value of products. Practically all the respondents have to deal either with shortlife cycle or low-value products, or both, stressing the importance of efficient reverse logistics handling. Yet, in spite of the increasing attention that reverse logistics is receiving in management literature, its full potential still appears to be under exploited in practice. Respondents consider reverse logistics processes to be out of control, especially for packaging and support materials and still with relatively modest management attention. In addition, we assess the future outlook and potential growth. Almost all companies expect an increase of management attention for reverse logistics, and the results show a l...
The most common approaches to solve the variants of the well-known vehicle routing problem are ba... more The most common approaches to solve the variants of the well-known vehicle routing problem are based on metaheuristic hill-climbing search. The deficiency of these methods is slow local search based hill climbing that often is restricted to limited local neighborhood. In this paper we suggest a novel new two-phase metaheuristic that escapes the local minima with jumps of varying size, instead of step by step local hill climbing. The initial solution is first generated with a powerful ejection pool heuristic. The key idea of the improvement phase is to combine large neighborhood search with standard guided local search metaheuristic in a novel way, allowing improved search diversification and escape from local minima in more efficient way through jumps. The algorithm has been tested on the standard Gehring and Homberger benchmarks for the vehicle routing problem with time windows and the results indicate very competitive performance. We found 12 new and 43 matched best-known solution...
This paper introduces the vehicle routing problem with partial outsourcing (VRPPO) in which a cus... more This paper introduces the vehicle routing problem with partial outsourcing (VRPPO) in which a customer can be served by a single private vehicle, by a common carrier, or by both a single private vehicle and a common carrier. As such, it is a variant of the vehicle routing problem with private fleet and common carrier (VRPPC). The objective of the VRPPO is to minimize fixed and variable costs of the private fleet plus the outsourcing cost. We propose two different path-based formulations for the VRPPO and solve these with a branch-and-price-and-cut solution method. For each path-based formulation, two different pricing procedures are designed and used when solving the linear relaxations by column generation. To assess the quality of the solution methods and gain insight in potential cost improvements compared with the VRPPC, we perform tests on two instance sets with up to 100 customers from the literature.
The team orienteering problem (TOP) aims at finding a set of routes subject to maximum route dura... more The team orienteering problem (TOP) aims at finding a set of routes subject to maximum route duration constraints that maximize the total collected profit from a set of customers. Motivated by a real-life automated teller machine cash replenishment problem that seeks for routes maximizing the number of bank account holders having access to cash withdrawal, we investigate a generalization of the TOP that we call the team orienteering problem with overlaps (TOPO). For this problem, the sum of individual profits may overestimate the real profit. We present exact solution methods based on column generation and a metaheuristic based on large neighborhood search to solve the TOPO. An extensive computational analysis shows that the proposed solution methods can efficiently solve synthetic and real-life TOPO instances. Moreover, the proposed methods are competitive with the best algorithms from the literature for the TOP. In particular, the exact methods can find the optimal solution of 371...
In the vehicle routing problem with multiple time windows (VRPMTW), a single time window must be ... more In the vehicle routing problem with multiple time windows (VRPMTW), a single time window must be selected for each customer from the multiple time windows provided. Compared with classical vehicle routing problems with only a single time window per customer, multiple time windows increase the complexity of the routing problem. To minimize the duration of any given route, we present an exact polynomial time algorithm to efficiently determine the optimal start time for servicing each customer. The proposed algorithm has a reduced worst-case and average complexity than existing exact algorithms. Furthermore, the proposed exact algorithm can be used to efficiently evaluate neighborhood operations during a local search resulting in significant acceleration. To examine the benefits of exact neighborhood evaluations and to solve the VRPMTW, the proposed algorithm is embedded in a simple metaheuristic framework generating numerous new best known solutions at competitive computation times.
The need to reduce pollution and traffic in city centers requires the use of small vans, electric... more The need to reduce pollution and traffic in city centers requires the use of small vans, electric vehicles, and drones to distribute goods. Because of autonomy and capacity issues, these vehicles need to perform multiple trips from/to the depot during the day. The category of decision-making problems modeling such distribution problems are known as multitrip vehicle-routing problems (MTVRPs), which generalize the well-known vehicle-routing problem by allowing vehicles to perform multiple trips per day. Several MTVRPs are solved in the literature with different mathematical models and algorithms. In “An Exact Solution Framework for Multitrip Vehicle-Routing Problems with Time Windows,” R. Paradiso, R. Roberti, D. Laganà, and W. Dullaert propose a single algorithm that can solve, to optimality, the MTVRP with capacity and time windows constraints and four variants of this problem featuring additional operational constraints. The proposed framework significantly outperforms the state-o...
International Journal of Operations & Production Management, 2019
Purpose The purpose of this paper is to develop propositions explaining the influence of individu... more Purpose The purpose of this paper is to develop propositions explaining the influence of individual goals and social preferences on human decision making in transport planning. The aim is to understand which individual goals and social preferences planners pursue and how these influence planners’ decisions. Design/methodology/approach Propositions are developed based on investigation of decision making of transport planners in a Dutch logistics service provider using multiple data collection methods. Findings The study shows how decision making of transport planners is motivated by individual goals as well as social preferences for reciprocity and group identity. Research limitations/implications Further research including transaction data analysis is needed to triangulate findings and to strengthen conclusions. Propositions are developed to be tested in future research. Practical implications Results suggest that efforts to guide planners in their decision making should go beyond t...
The International Journal of Logistics Management, 2019
PurposeThe purpose of this paper is to establish criteria for evaluating strategic partners in a ... more PurposeThe purpose of this paper is to establish criteria for evaluating strategic partners in a network of logistics service providers (LSPs) to show how analytical network process (ANP) can be used to identify the weights of these criteria on a case-specific basis, and to investigate whether the ANP model can be used as a starting point to evaluate strategic partners for other LSP networks.Design/methodology/approachBased on a literature review of vertical cooperation, the authors develop an overview of criteria for the evaluation of partners in a network of LSPs. The authors then apply ANP at LSP1 to validate the criteria, identify weights for these criteria and to validate model outcomes. Furthermore, the authors investigate whether the ANP model developed for LSP1 can be applied to another LSP with similar characteristics (LSP2). In-depth interviews are used to draw conclusions on the modeling approach and the model outcomes.FindingsThe research shows that evaluation criteria f...
The International Journal of Logistics Management, 2018
PurposeThe purpose of this paper is to present a literature review that aims to provide insight i... more PurposeThe purpose of this paper is to present a literature review that aims to provide insight into the characteristics and effectiveness of supply chain visibility (SCV), as well as to identify metrics that capture these aspects in business processes.Design/methodology/approachA systematic review of the supply chain literature is conducted to identify the characteristics and the effectiveness of SCV. The synthesis of SCV effectiveness and its metrics are based on the process-oriented approach which relates the effectiveness of SCV to improved business performance.FindingsThis study reveals that the characteristics of SCV can be captured in terms of the accessibility, quality, and usefulness of information. The benefits of SCV are found to extend beyond improvements to operational efficiency of business processes or to the strategic competencies of an organization.Practical implicationsThis study underlines that clear agreements between all players involved in the SC can help to so...
Supply Chain Management: An International Journal, 2017
Purpose The aim of this paper is to conduct a systematic literature review to understand the stat... more Purpose The aim of this paper is to conduct a systematic literature review to understand the state of the art of partnerships between humanitarian organizations and business corporations in managing humanitarian logistics. Design/methodology/approach A systematic literature review is conducted based on the steps proposed by Denyer and Tranfield (2009). The context-intervention-mechanism-outcome (CIMO) logic is applied to identify the state of the art of partnerships between humanitarian organizations and business corporations in humanitarian logistics. Thirty-six papers related to the topic are extracted from recognized journal databases and then classified into four categories based on the CIMO logic: situational context, intervention factors, mechanisms and outcomes. Findings The study shows that while the context and mechanisms for developing cross-sector partnerships between the humanitarian and the business sector have been examined and illuminated by many researchers, addition...
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Papers by Wout Dullaert