Browsing by Author "Ertem, Mustafa Alp"

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A Procurement Auctions-Based Framework for Coordinating Platforms in Humanitarian Logistics
(2013) Ertem, Mustafa Alp; Buyurgan, Nebil; 52460; Endüstri Mühendisliği
This chapter focuses on an auction-based procurement framework for single coordinating platforms in humanitarian logistics. It first covers disaster relief operations, humanitarian logistics, and procurement in this context and illustrate many of the issues that make the management and coordination of procurement functions complex and challenging. Then the proposed framework along with the auction model is discussed including the unique design characteristics associated with disaster relief environment. Three-phase approach presents a complete representation of the procurement in humanitarian logistics. Results indicate that the proposed announcement options increase the fill rate. Announcement construction criteria allow coordinating platforms to use varying bundling choices.
Citation - WoS: 6
Citation - Scopus: 10
A Warehouse Design With Containers For Humanitarian Logistics: A Real-Life Implementation From Turkey
(Univ Cincinnati industrial Engineering, 2019) Sahin-Arslan, Aysenur; Ertem, Mustafa Alp; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği
The purpose of this study is to investigate how and at what cost freight containers could be used as an inventory holding mechanism for humanitarian logistics. The layout and cost comparison of two alternatives are performed-stocking in a warehouse and material storage in containers. An optimum layout for storage in containers is proposed. It was found that container stockpiling uses the available area and space better than the warehouse option to stock the same number of material pallets. Leasing and purchasing costs of these alternatives are compared using present worth analysis. The results revealed that the container leasing option is not cost effective when land cost is included. Warehouse leasing results in the least setup cost, however, it incurs more operating costs, including lighting, ventilation, and maintenance as well as handling of the pallets. A real-life implementation of the proposed container stockpiling idea is presented for Turkey.
Citation - WoS: 29
Citation - Scopus: 33
An Auction-Based Framework for Resource Allocation in Disaster Relief
(Emerald Group Publishing Ltd, 2011) Ertem, Mustafa Alp; Ertem, Mustafa Alp; Buyurgan, Nebil; 52460; Endüstri Mühendisliği
Purpose - 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.
Citation - WoS: 15
Citation - Scopus: 17
Determination of equivalent warehouses in humanitarian logistics by reallocation of multiple item type inventories
(Elsevier, 2021) Demirbas, Sefika; Ertem, Mustafa Alp; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği
Prepositioning freight containers for storage of relief supplies can be considered an alternative to warehousing with shelves. Recently, 25 container warehouses are located in different cities in Turkey to deliver relief supplies to beneficiaries quickly. We take this existing situation as given and investigate if this investment could be utilised better. The available inventory (i.e., tents, beds, blankets) in these container warehouses is currently not used efficiently. Some warehouses store one type of item and none from other types. Therefore, several warehouses must be activated during a response operation to fully satisfy the beneficiaries' needs for each relief item type. We aim to investigate the benefits of operating equivalent (i.e., a proper inventory level from each relief item type) warehouses while reallocating a total available inventory for better coordination. A locationreallocation type of mathematical model is tested with real-life data from past earthquakes. Three to eight container warehouses are recommended to be converted to an equivalent type. The results indicate potential savings for the proposed model, and this potential is more visible in large-scale demand instances than in small ones.
Citation - Scopus: 0
Forecasting day of week volume fluctuations in the intermodal freight transportation
(Institute of Industrial Engineers, 2011) Ertem, M.A.; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği
Average daily volume fluctuates intensely based on the day of week in the intermodal freight transportation. Shippers tend to peak around Thursdays and receivers tend to peak around Mondays. These fluctuations bring challenges to the industry in terms of capacity management and getting reliable service from the railroad companies. The purpose of this study is to forecast J. B. Hunt Transport Services, Inc.'s load volume on railroads. Load is meant to be the number of containers that will arrive at a rail ramp during a 24hrs time window. The end in mind is to have better service from the railroad companies and to manage the company owned equipment better. The forecasting model applied to tackle this problem is a multiple linear regression model and is based on the historical in-gate numbers. It uses the previous two year's data and day of week information as independent variables, and current year's data as the response variable. The results indicate better accuracy levels for the model when compared to the two week moving average.
Citation - WoS: 16
Citation - Scopus: 17
Freight transportation using high-speed train systems
(Taylor & Francis Ltd, 2016) Ertem, M. A.; Ertem, Mustafa Alp; Ozcan, M. Keskin; 52460; 52460; Endüstri Mühendisliği
This study investigates the use of high-speed trains (HSTs) for transporting freight, such as small cargo and mail. A HST scheduling model is constructed to observe the effects of including freight in a passenger-only system. The proposed mathematical model is tested with an experimental study using the Turkish State Railways high-speed rail network and train sets. Freight transportation is analyzed in two cases, namely, adding separate freight trains to the system and using passenger trains for freight transportation. It can be concluded that dividing the sequences of cities into two allows for the completion of train services earlier in the day, and using the same train for transporting both passengers and freight provides more time saving in the system.
İnsani Yardım Lojistiği için Konteyner Deposu Tasarımı
(2019) Ertem, Mustafa Alp; Şahin Arslan, Ayşenur; 52460; Endüstri Mühendisliği
Citation - WoS: 30
Citation - Scopus: 38
Intermodal humanitarian logistics model based on maritime transportation in Istanbul
(Springer, 2016) Ertem, Mustafa Alp; Ozkapici, Dilsu Binnaz; Ertem, Mustafa Alp; Aygüneş, Haluk; Aygunes, Haluk; 52460; 57149; Endüstri Mühendisliği
Istanbul, the economic capital and most populated city of Turkey, is highly prone to earthquakes. When an earthquake occurs, required relief items are expected to be supplied from national and international sources. To alleviate human suffering following an earthquake, in this paper, we propose an intermodal relief item distribution model for Istanbul involving sea and land transportation with identified road vulnerabilities. The proposed mathematical model utilizes the seaports of Istanbul for maritime transportation and allows for the transportation of relief item between Istanbul's European and Anatolian sides. We also use the seabasing concept for providing supplies to demand areas. The use of maritime transportation and seabasing provides flexibility for humanitarian logistical activities and the proposed model provides an effective and reliable disaster relief system for Istanbul as well as other disaster-prone cities with significant maritime transportation components.
Citation - WoS: 6
Citation - Scopus: 6
Intermodal Humanitarian Logistics Using Unit Load Devices
(Springer Heidelberg, 2022) Kavlak, Hasan; Kavlak, Hasan; Ertem, Mustafa Alp; Ertem, Mustafa Alp; Satir, Benhur; Satır, Benhür; 57708; 52460; 54700; Endüstri Mühendisliği
Intermodal 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.
Citation - WoS: 11
Citation - Scopus: 15
Intermodal transportation in humanitarian logistics with an application to a Turkish network using retrospective analysis
(Elsevier, 2022) Ertem, Mustafa Alp; Ertem, Mustafa Alp; Akdogan, Muharrem Altan; Kahya, Melike; 52460; Endüstri Mühendisliği
In the event of disruptions in a transportation network following a disaster, humanitarian organizations find it challenging to provide basic requirements for beneficiaries. Demand may be met using intermodal transportation as an alternative when the unimodal transportation infrastructure is damaged. This study proposes a mathematical model for utilizing intermodal transportation using 40 ft standard containers while delivering relief supplies by road, rail, and sea modes. The proposed model is a capacitated multi-period multicommodity intermodal network flow model in which relief supplies are delivered to beneficiaries in three echelons (i.e., supply, intermodal hub, and demand). The Turkish Disaster and Emergency Management Presidency's container warehouses (i.e., supply), logistics centers and container ports (i.e., intermodal hubs) are utilized to test the mathematical model with real-life demand parameters. Retrospective analysis was performed to determine the most frequently used container warehouses, logistics centers, and origin-destination pairs. Hence, an increase in operational capacity and infrastructure reinforcement is recommended to mitigate the effects of future disasters. We found that intermodal transportation is more robust to network disruptions in rapidly delivering relief supplies. We observed that intermodal transportation is utilized in disasters with more than 50,000 beneficiaries or disrupted unimodal infrastructure. For instance, after the future Istanbul earthquake, it would be impossible to deliver the relief materials only by road transportation within the urgent response period. Thus, the benefits of intermodal transportation in humanitarian logistics are more visible in large-scale disasters in which transportation resources are scarce, and transportation infrastructure is more likely to be destroyed.
İntermodal Yük Taşımacılığı ile Sürdürülebilir İnsani Yardım Lojistiği
(2016) Ertem, Mustafa Alp; Ertem, Mustafa Alp
Proje, intermodal yük taşımacılığı ille sürdürülebilir insani yardım lojistiği konusunda bir araştırma projesidir.
Citation - WoS: 285
Citation - Scopus: 347
Models, solutions and enabling technologies in humanitarian logistics
(Elsevier Science Bv, 2015) Ozdamar, Linet; Ertem, Mustafa Alp; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği
We present a survey that focuses on the response and recovery planning phases of the disaster lifecycle. Related mathematical models developed in this area of research are classified in terms of vehicle/network representation structures and their functionality. The relationships between these characteristics and model size are discussed. The review provides details on goals, constraints, and structures of available mathematical models as well as solution methods. In this review, information systems applications in humanitarian logistics are also surveyed, since humanitarian logistics models and their solutions need to be integrated with information technology to enable their use in practice. (C) 2014 Elsevier B.V. All rights reserved.
Citation - WoS: 41
Citation - Scopus: 46
Pre-positioning of relief items in humanitarian logistics considering lateral transhipment opportunities
(Elsevier Science inc, 2017) Baskaya, Serhat; Ertem, Mustafa Alp; Ertem, Mustafa Alp; Duran, Serhan; 52460; 164958; Endüstri Mühendisliği
The main objective of this study is to investigate the inclusion of lateral transhipment opportunities into the humanitarian relief chain and to examine the effect of different parameters on minimizing the average distance travelled per item while serving the beneficiaries. Direct shipment model (DT), lateral transhipment model (LTSP) and maritime lateral transhipment model (MLTSP) are developed and compared between each other by using a real life earthquake scenario prepared for the city of Istanbul by JICA (Japanese International Cooperation Agency). Developed mathematical models decide on the locations and number of disaster relief facilities, quantity of relief items to hold at those facilities, and quantity of lateral transhipment between the facilities. Vulnerability of the roads and heterogeneous capacitated facilities are also considered. It can be concluded that both LTSP and MLTSP models gave better results than DT model and lateral transhipment option helps beneficiaries to obtain relief items faster and with higher service level. (C) 2016 Elsevier Ltd. All rights reserved.
Program Çıktıları İçin Alternatif Bir Ölçme- Değerlendirme Modeli: MÜDEK Karnesi
(2019) Ertem, Mustafa Alp; Özaktaş, Hakan; Ertem, Mustafa Alp; Kırkavak, Nureddin; 52460; Endüstri Mühendisliği
Lisans mühendislik eğitimi için akreditasyon, rekabetin sürekli arttığı dünyamızdamühendislik fakülteleri için olmazsa olmaz bir kalite güvencesi haline gelmektedir.Ülkemizde mühendislik lisans programlarının akreditasyonu için yetkili kurum‘Mühendislik Eğitim Programları Değerlendirme ve Akreditasyon Derneği’(MÜDEK)’dir. MÜDEK akreditasyonu konusunda önceden tecrübe edinmişmühendislik eğitimi veren birçok bölüm olmasının yanında bu sürece yeni girecekya da süreçte zorluklar yaşayan bölümler için başarılı deneyimlerin paylaşılmasıda büyük önem taşımaktadır. Akreditasyon sürecinde çekilen zorluklardan enönemlisi olduğuna inandığımız konu ise program çıktılarının nesnel ölçmedeğerlendirme gereçleri kullanılarak program çıktılarının her mezunakazandırıldığının belgelenmesidir. Bu çalışmada entegre bir özgün yaklaşım ile,mezun olan her öğrenci için mikro ve makro boyutlarda geliştirilen modellerçerçevesinde mühendislik eğitiminde hedeflenen ideale ulaşmak amacıyla sürekliiyileştirme sürecini de işleten bir deneyim üzerinden açıklanmaktadır.
Citation - WoS: 25
Citation - Scopus: 28
Review of intermodal freight transportation in humanitarian logistics
(Springeropen, 2017) Ertem, Mustafa Alp; Ertem, Mustafa Alp; Isbilir, Melike; İşbilir, Melike; Arslan, Aysenur Sahin; 52460; 21838; Endüstri Mühendisliği
Purpose 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.
Türkiye’de Lojistik Sektörü ve Devlet Malzeme Ofisi’nin Durumu
(2016) Ertem, Mustafa Alp; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği
Devlet Malzeme Ofisi (DMO), kamu kurumlarının belirli ihtiyaçlarını satınalma görevini üstlenmiş bir Kamu İktisadi Teşebbüsü (KİT)'dür. Bu çalışmanın amacı DMO'nun lojistik açıdan mevzuattaki yükümlülükleri ile lojistik faaliyetlerini incelemek ve DMO'ya alternatif seçenekler sunmaktır. Bu çalışmanın özgün yönü Türkiye'de 60 yıldır merkezi satınalma kuruluşu olarak görev yapan DMO'nun lojistik yükümlülüklerinin, hâlihazırdaki lojistik faaliyetlerinin durumunun ve geliştirme önerilerinin ilk defa sunulmuş olmasıdır. Öneriler depolama, taşımacılık ve tesis yeri seçimi alt konularında sunulmuştur. DMO için en olası senaryolar (1) Mevcut depolardan maliyet etkin olmayanların kapatılarak sezonluk depoların kiralanması, (2) DMO araçlarıyla yapılan nakliyenin azaltılması ve (3) Kapatılacak/kiralanacak depolar için yer tespiti olarak sıralanabilir
Citation - WoS: 14
Citation - Scopus: 18
Using containers as astorage facilities in humanitarian logistics
(Emerald Group Publishing Ltd, 2014) Ertem, Mustafa Alp; Ertem, Mustafa Alp; Emur, Emel; Endüstri Mühendisliği
Purpose - The purpose of this paper is to investigate the use of freight containers to store relief items instead of operating a permanent warehouse building. Design/methodology/approach - A mathematical model is developed to determine the location and quantity of containers as well as the type and amount of relief supplies to store in order to investigate the practicality of using freight containers for storage. The model is tested using earthquake risk data, estimates of population under risk, and the distances between cities. An experimental study is performed using Turkish Prime Ministry Disaster and Emergency Management Presidency (abbreviated as AFAD in Turkish) data for total number of relief supplies. Findings - Considering the earthquake risk of possible locations, the results of the study indicate the target locations for containers. The idea of using containers as storage facilities helped beneficiaries to be reached within a short distance and in an efficient way. Research limitations/implications - The presented model is not implemented in real life disaster relief operations even if it is tested with real earthquake risk, demand and distance data. Practical implications - To apply this model in practice, the container locations within cities should be determined and managerial operations such as maintenance, environmental, and security planning have to be considered. Originality/value - This study presents the first analysis of three sub-topics' intersection: warehousing, pre-positioning in disaster relief, and containerization. To the best of authors' knowledge, containers have not been considered for storage of relief items in humanitarian logistics before.