Speaker: Barış Yıldız, Koç Üniversitesi
Title: Consolidation in Crowdshipping with Scheduled Transfer Lines: A Surrogate-Based Network Design Framework
Date: 3rd October 2025, Friday
Time: 13:30
Place : EA409
Abstract: Crowdshipping has gained attention as an emerging delivery model thanks to advantages such as flexibility and an asset-light structure. Yet, it chronically suffers from a lack of mechanisms to create and exploit consolidation opportunities, limiting its efficiency and scalability. This work contributes to the literature in two ways: first, by introducing a novel consolidation concept that augments crowdshipping networks with dedicated scheduled delivery lines; and second, by developing a new methodology for solving complex network design problems, exemplified by the case studied in this paper, where design decisions needs to be made while taking complex operational dynamics into account, yet realistic representations of these dynamics are difficult to incorporate compactly into mathematical models. To address this challenge, we embed a neural network surrogate within a mathematical programming framework. The surrogate is based on a novel architecture that explicitly exploits the binary nature of design decisions, a feature common to many such problems. We establish theoretical guarantees regarding approximation accuracy and proximity to the true optimum. Numerical experiments with real-world data demonstrate both the practical benefits of the proposed hybrid delivery model—reducing costs, traffic, and emissions—and the computational advantages of the proposed solution framework.
Short Bio: Barış Yıldız received his Ph.D. from Bilkent University Industrial Engineering Department in 2016. He holds an M.S. degree in Operations Research from the U.S. Naval Postgraduate School and a B.S. degree in Systems Engineering from the Turkish Army Academy. He joined the Koc University Industrial Engineering Department in 2016 as a faculty member. His research focuses on network design and management problems in transportation and logistics that appeared in prestigious journals, including Operations Research, Transportation Science, Production and Operations Management, Transportation Research Part B, C, E, and EJOR. Dr. Yıldız is the recipient of the 2018 INFORMS SOLA Best Dissertation Award, 2019 Turkish Science Academy High Achieving Young Scholar Award, and INFORMS 2023 Chuck ReVelle Rising Star Award. His research has been supported by TUBITAK early-career and research-development grants. Dr. Yıldız is also the recipient of the ERC Starting Grant that aims to develop novel approaches to conceptualize, design, and manage city logistics.