Dynamic Agent-based Scheduling of Treatments: Evidence from the Dutch Youth Health Care Sector

Citation Erik Giesen, Wolf Ketter, Rob Zuidwijk (2015). Dynamic Agent-based Scheduling of Treatments: Evidence from the Dutch Youth Health Care Sector, pp. 173-199 in: Multiagent System Technologies. Lecture Notes in Computer Science 9433. Jörg P. Müller, Wolf Ketter, Gal Kaminka, Gerd Wagner, Nils Bulling (Eds.), Springer.

Link http://dx.doi.org/10.1007/978-3-319-27343-3_10

Abstract We use agent-based simulation to compare the performance of four scheduling policies in youth health care. The policies deploy push/pull and centralized/decentralized concepts. The simulation model represents an authentic business case and is parameterized with actual market data. The model incorporates, among other things, non-stationary Poisson arrival processes, reneging and return mechanisms, and care provider’s client preferences. We have identified that performance measurement in youth health care should not be focused on queue lengths alone, which is presently the case, but should include a case difficulty parameter as well. The simulation results, together with contextual data obtained from stakeholder interviews, indicate that a push strategy with a centralized queue suits the sector best, which is different from the current real-world situation. This policy ensures a higher level of fairness in treatment provision because the care providers are compelled to take their share in treating the difficult and economically less attractive cases. The complexity of the case cannot be captured by current queuing theory methods. Our simulation approach incorporates these complexities, which turn out to be relevant for the scheduling policy decision. We validate the model and strategies using real market data and field expert discussions.

Towards Efficient Multimodal Hinterland Networks

Citation Albert Veenstra and Rob Zuidwijk (2015). Towards Efficient Multimodal Hinterland Networks, pp. 55-66 in: Logistics and Supply Chain Innovation. Lecture Notes in Logistics. Henk Zijm, Matthias Klumpp, Uwe Clausen, Michael ten Hompel (Eds.), Springer.

Link https://dx.doi.org/10.1007/978-3-319-22288-2_4

Abstract Terminal operator ECT in the port of Rotterdam sought to establish a multidisciplinary research group that would support the development of a strong multimodal hinterland network concept. This was the start of the ULTIMATE project. ULTIMATE aimed to support the development “towards efficient multimodal hinterland networks”. The Ultimate research agenda consisted of four elements: (1) The operational consequences of integrating transport and cargo handling activities for supply chains. This has resulted in efficient container stacking and barge routing algorithms. (2) Incorporating new business models in the design of hinterland networks. This delivered new insights in the role of information and pricing in hinterland networks. (3) The legal consequences of mixing transport and storage activities by container terminals. The contribution of this element is a more fundamental understanding of the importance of legal concepts in multimodal transport for different actors. (4) The role and position of the port authority vis-a-vis the activities of container terminals. This led to new insights on the role and contribution of a port authority in port and hinterland network development. This chapter discusses some of the main research outcomes of the work for these four research problems.

Minimizing cost of empty container repositioning in port hinterlands, while taking repair operations into account

Citation Thomas Hjortnaes, Bart Wiegmans, Rudy Negenborn, Rob Zuidwijk, Rick Klijnhout (2017). Minimizing cost of empty container repositioning in port hinterlands, while taking repair operations into account. Journal of Transport Geography 58(1): 209-219.

Link http://dx.doi.org/10.1016/j.jtrangeo.2016.12.015

Abstract Shipping companies are striving to optimize their empty container repositioning strategies which also contribute to reduced congestion and environmental improvements. In this paper we propose a multi-commodity model that makes an explicit distinction between flows of non-damaged containers, on the one hand, and flows of damaged containers, on the other. The model is tailored for the repositioning of these containers in the representative setting of a network of off-dock empty depots, ocean terminals, and inland terminals. In our case study, cost savings of up to 17% are found, depending on the composition of the network, container type, and particular evacuation and repositioning strategy. In particular, directly transporting containers from inland terminals to other inland terminals (direct repositioning) results in cost savings of up to 15% for dry containers and up to 17% for reefer containers. Furthermore, the total costs might be optimized by actually preventing the container failure from occurring possibly leading to considerable additional cost reductions. Finally, exporting damaged containers might seem to be the optimal solution from a regional cost perspective, but, this does not necessarily lead to total cost optimization from the global perspective.

Multimodal schedule design for synchromodal freight transport systems

Citation Behzad Behdani, Yun Fan, Bart Wiegmans, Rob Zuidwijk (2016). Multimodal schedule design for synchromodal freight transport systems. European Journal of Transport and Infrastructure Research 16(3): 424-444.

Link http://tlo.tbm.tudelft.nl/fileadmin/Faculteit/TBM/Onderzoek/EJTIR/Back_issues/16.3/2016_03_00.html

Abstract Intermodal freight transport has been discussed for decades as an alternative to unimodal road transport. However, it still does not represent a significant portion of the total freight market. A new and promising possibility to improve the performance of freight systems is the synchromodal design of hinterland transport systems. A cornerstone for synchromodality is an integrated view in the design and operation of intermodal transport. A main benefit of this integrated view is an improved flexibility in mode choice in hinterland transport. This paper gives a detailed description of this integrated view for synchromodal freight transport. Based on this description, a mathematical model for designing service schedules for synchromodal freight transport systems is also presented. The benefits of providing integrated transport services compared to separately planned transport services are also discussed for a case in the hinterland network of the Port of Rotterdam.