Endüstri Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/279
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Article Citation - WoS: 8Citation - Scopus: 9Intermodal Humanitarian Logistics Using Unit Load Devices(Springer Heidelberg, 2022) Kavlak, Hasan; Ertem, Mustafa Alp; Satir, BenhurIntermodal freight transportation facilitates today's global trade. The benefits of intermodal freight transportation have been studied and are more observable in commercial logistics; however, the potential benefits of humanitarian logistics have not been thoroughly investigated. This research aims to present a resilient transportation framework by modeling intermodal transportation utilizing interoperable loading devices during disaster responses. We developed an integer programming model based on a time-space network by considering route and vehicle availabilities that are allowed to change with time. We consider vehicles with varying capacities in three transportation modes (i.e., ground, maritime, and air). The contribution of this study is threefold: (1) Two compatible unit load devices are proposed for humanitarian logistics; (2) a mathematical model that includes integer variable representation for vehicle fleets in different transportation modes is developed; and (3) intermodal transportation is compared with single-mode transportation using a real-life dataset. Our main results are as follows: In terms of cost, intermodal transportation is effective when demand occurs in consecutive periods and response time is short. Inventory is held more in intermodal transportation when it is cost-effective to use transportation modes with large capacities. Thus, the benefits of the responsiveness of intermodal transportation outweigh the costs of mode interchange and inventory holding for sudden-onset disasters where quick responses are needed within a short time.Article Citation - WoS: 30Citation - Scopus: 34An Auction-Based Framework for Resource Allocation in Disaster Relief(Emerald Group Publishing Ltd, 2011) Buyurgan, Nebil; Ertem, Mustafa Alp; Alp Ertem, MustafaPurpose - The purpose of this paper is to address the inefficiency problems in procurement operations in disaster relief logistics which are mainly due to the lack of coordination among less organized suppliers and partnerships. Such problems lead to poor responsiveness and hinder timely procurement of required goods. Design/methodology/approach - An auction-based framework for procurement of goods, which is suitable for a single coordinating platform in disaster relief logistics, is proposed. Integer programming formulations are used in auctioning operations. A simulation model that generates problem instances is used to evaluate and tune system-level design parameters. Findings - Design parameters greatly affect the behaviour and responsiveness of the system and the performance of the auction-based framework in different problem instances. Combinations of those parameters may allow suppliers with limited capacities to become more involved in the bidding process. In addition, the procurement shares of bidders may change substantially with different values of the parameters. Research limitations/implications - Even though the presented framework is inspired from reallife applications, it is not implemented in real-life disaster relief operations. The goodness of fit for the framework would best be evaluated by a real disaster case. In addition, transportation scheduling and vehicle routing considerations and budgeting issues are not considered in the framework. Originality/value - This paper presents an auction-based framework for less organized suppliers of goods and their partnerships, such as local humanitarian organizations, private companies, and standby partners. The presented framework offers a background for coordination during disaster relief operations which provides opportunities to act as a set of organized entities. This background also helps those entities coordinate their efforts to enhance the capabilities of local governments and NGOs.Article Citation - WoS: 31Citation - Scopus: 35Review of Intermodal Freight Transportation in Humanitarian Logistics(Springeropen, 2017) Arslan, Aysenur Sahin; Ertem, Mustafa Alp; Isbilir, Melike; Şahin Arslan, AyşenurPurpose Using intermodal transportation is vital for the delivery of relief supplies when single mode alternative becomes unusable or infeasible. The objective of this paper is to investigate the use of intermodal freight transportation in humanitarian logistics. Methods This paper first identifies the differences between multimodal and intermodal transportation. Then, we examine the use of each transportation mode for specific disaster types and phases. When combinations of transportation modes (i.e. air, road, rail and sea) for intermodal transportation are considered together with different disaster types (e.g. earthquake, flood and famine), the feasible decision space becomes rather large. To explore this decision space, we have reviewed the academic and practitioner studies as well as several non-governmental organizations (NGO)' disaster archives. Results From this exploration, we developed a transportation mode/disaster-type combination matrix and a transportation mode/disaster-phase combination matrix. We then discuss examples of real life usage of intermodal transportation in humanitarian logistics and share our findings and analyses. Of 369 academic humanitarian logistics articles, only 20 have mentioned transportation mode changes. In practitioner studies, we found a decreasing percentage of the usage of slower modes (e.g. sea and rail) in the disaster response phase over time. We were not able to find a significant relationship between a specific transportation mode and a specific disaster-type or - phase. Road transportation seems to cover most of the disaster operations regardless of the disaster-type or - phase. Conclusions We can conclude that intermodality and the transportation unit concept is not being studied extensively in humanitarian logistics. Most of the relief organizations do not share transported freight amounts in their reports and those that do share transported freight amounts in their reports do not explicitly mention mode changes. We discuss the enablers of and obstacles to the effective use of intermodal transportation in humanitarian logistics and propose future research directions. We anticipate that intermodal transportation in humanitarian logistics will garner greater research attention and increased utilization in coming years.