文章基本信息

标题：MIXED-INTEGER PROGRAMMING FORMULATIONS FOR THE TRUCK SCHEDULING PROBLEM WITH FIXED OUTBOUND DEPARTURES
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作者：Pascal Wolff ; Jiazhen Huo ; Hans-Christian Pfohl 等
期刊名称：LogForum
电子版ISSN：1734-459X
出版年度：2021
卷号：17
期号：2
DOI：10.17270/J.LOG.2021.572
语种：English
出版社：Poznań School of Logistics
摘要：Background: Truck scheduling at cross-docking terminals has received much academic attention over the last three decades. A vast number of mixed-integer programming models have been proposed to assign trucks to dock-doors and time slots. Surprisingly, only a few models assume fixed outbound truck departures that are often applied in the less-than-truckload or small parcel and express delivery industry. To the best of our knowledge, none of these papers explore whether a discrete-time or continuous-time model formulation has a better computational performance. This paper attempts to close this research gap and tries to shed light on which type of formulation is advantageous. Therefore, a variant of the truck scheduling problem with fixed outbound departures is considered. This problem's objective is to find a feasible truck schedule that minimizes the number of delayed freight units. Methods: We propose two model formulations for the described variant of the truck scheduling problem with fixed outbound departures. Specifically, the problem is formulated as a discrete-time and a continuous-time mixed-integer programming model. Results: A computational experiment is conducted in order to assess the computational performance of the presented model formulations. We compare the discrete-time and continuous-time formulation in terms of both the solution quality and computational time. Conclusions: The computational results show that the proposed discrete-time model formulation can solve problem instances of medium size to proven optimality within less than one minute. The continuous-time model formulation, on the other hand, can solve small instances to optimality. However, it requires longer solution times than the discrete-time formulation. Furthermore, it is unable to solve medium-sized instances within a 5-minute time limit. Thus, it can be summarized that the proposed discrete-time model formulation is clearly superior to the continuous-time model formulation.
关键词：cross-docking;truck scheduling;mixed-integer programming;logistics;optimization