Browsing by Author "Aktas, Emel"

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Citation - Scopus: 2
Additive manufacturing and its impact on pharmaceutical supply chains
(Elsevier, 2024) Wenqi Li; Banu Yetkin Yetkin Ekren; Emel Aktas; Li, Wenqi; Aktas, Emel; Ekren, Banu Y.
Additive manufacturing (AM) also known as 3D printing has the potential to improve the performance of the pharmaceutical supply chain (PSC). By using 3D printing for manufacturing drugs pharmaceutical companies can reduce waste by using only the required number of raw materials and eliminating excess inventory. This chapter will provide a systematic literature review of the state of the art of AM in PSC and develop a conceptual framework to explain their interconnections. It was found that 3D printing impacts the SC in three main ways: reducing complexity moving manufacturing facilities closer to the end user and shifting production from make-to-stock to make-to-order. These changes influence the inventory level which in turn affects SC sustainability efficiency responsiveness and resilience. This study provides a conceptual framework that illustrates the interrelationships between various variables in the medical SC impacted by 3D printing technology. © 2024 Elsevier B.V. All rights reserved.
Comparison of efficiencies in protectionist and liberal cabotage policies
(ROUTLEDGE JOURNALS TAYLOR & FRANCIS LTD, 2025) Deniz Karagoz; Mehmet Fatih Acar; Emel Aktas; Anil Aba; Aba, Anil; Karagoz, Deniz; Acar, Mehmet Fatih; Aktas, Emel
This paper focuses on cabotage which is a long-standing regulation that restricts coastal trade to domestic ships. As globalisation has grown global trade organisations have pushed for the removal of these barriers to promote a competitive market environment. In this research Data Envelopment Analysis (DEA) is used to evaluate and compare the efficiencies of countries which have protectionist and liberalised cabotage policies. To do this maritime statistics in 2022 from the World Bank database are considered for 50 different countries. We find that both protectionist and liberal policies have advantages and disadvantages but neither is inherently superior. In addition cabotage policies must be structured according to each country's conditions and a delicate balance must be established between these policies considering the dynamics of the global economy. This paper has also considered advantages and disadvantages by comparing countries that have different policies on cabotage such as the UK and T & uuml,rkiye to show how cabotage regulations generate different perspectives created by their respective maritime pasts and geopolitics. In terms of an effective and competitive maritime industry the study is one of the unique types of research that underlines the need for a cabotage strategy balanced between the liberalised and protectionist components.
Reimagining Salmon Supply Chains: A Sustainability Comparison of 3D-Printed and Traditional Production
(Elsevier, 2025) Li, Wenqi; Aktas, Emel; Ekren, Banu Y.
The seafood industry faces growing sustainability challenges, including overfishing, resource inefficiency, and environmental degradation, necessitating innovative production alternatives. While traditional SCs benefit from established infrastructure and consumer trust, their high resource demand and operational inefficiencies highlight the need for sustainable alternatives. This study compares traditional and 3D-printed salmon SCs, using process mapping by flowcharting and sustainability metrics to evaluate their environmental, economic, and social impacts. Findings indicate that 3D -printed salmon reduces carbon emissions by up to 86% and freshwater consumption by 95%, primarily by eliminating farming, feed production, and long-distance cold storage. Additionally, localized production lowers logistical costs and enhances resource efficiency. Despite challenges related to consumer acceptance, regulatory approval, and scalability, 3D printing presents a promising complement to aquaculture, supporting long-term sustainability in seafood production. Copyright (C) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Citation - WoS: 9
Sustainable e-grocery home delivery: An optimization model considering on-demand vehicles
(PERGAMON-ELSEVIER SCIENCE LTD, 2025) Vittoria Tudisco; Sara Perotti; Banu Yetkin Ekren; Emel Aktas; Perotti, Sara; Tudisco, Vittoria; Aktas, Emel; Ekren, Banu Yetkin
The e-grocery sector has experienced a significant boost since the COVID-19 pandemic dramatically changing consumer buying behaviours. As demand for faster and more efficient delivery options grows e-grocery retailers face increasing pressure to optimize home delivery operations. Collaborations with third-party logistics providers (3PLs) although still overlooked have emerged as promising offering operational flexibility and environmental benefits. This work introduces an optimization model that supports the design of an on-demand delivery fleet conjunctly with delivery routings and schedules while considering both cost and environmental impact. To this aim a vehicle routing problem with time windows (VRPTW) is extended to incorporate on-demand fleet design and three different objective functions embodying a cost-efficient an environmentally-effective and a costenvironmental balanced perspective respectively. Numerical experiments based on an Italian case study show that prioritizing environmental objectives reduces emissions by over 90% with marginal increases in annual costs. Besides on-demand vehicles enable flexibility that facilitates the adoption of sustainable delivery options without requiring challenging investments such as delivery fleet. Several contributions are provided: insights into using on-demand vehicles are proposed, a mathematical model jointly optimizing fleet design and delivery routing and scheduling while considering both costs and environmental objectives is developed and its practical application is demonstrated using real-world data. The findings highlight the significant impact of environmental considerations on fleet composition and operational efficiency offering actionable strategies for e-retailers to reduce emissions while maintaining service quality.