Bulanık çok kriterli karar verme teknikleri ile sürdürülebilir tedarik zinciri yönetimi ve tedarikçi seçimi
Fuzzy multi-criteria decision-making used in supplier selection and sustainable supply chain management
Yazar: BURHAN ÜLKER
Danışman: DR. ÖĞR. ÜYESİ TİJEN ÖVER ÖZÇELİK
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / İmalat Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2024
Konu: Endüstri ve Endüstri Mühendisliği = Industrial and Industrial Engineering

Özet:
Son yıllarda sürdürülebilirlik yaklaşımı oldukça önem kazanmıştır. Gün geçtikçe çok daha fazla sayıda şirket, tedarikçi ilişkilerini ve tedarikçinin yaşam süresini iyileştirme ve önceden riskleri belirleyebilmek amacıyla prosedür ve sözleşmelerini tedarik zincirinin tamamını kapsayacak biçimde genişletmektedir. Global ve yerli en büyük şirketler peşpeşe sürdürülebilirlik ilkelerini yayınlıyor, yeni departmanlar açarak bu konuya ne kadar önem verdiklerini gösteriyorlar. Bugünün nesillerinin gereksinimlerini giderirken gelecek nesillerin ihtiyaçlarını şimdiden planlamak çok kritiktir. Bu çalışmada, tedarikçi değerlendirme ve seçme sürecine sürdürülebilirlik başlığının eklenmesiyle günümüz şartlarına daha uygun hale getirilerek ve objektif değerlere bağlı kalınması amaçlanmaktadır. Çevresel, ekonomik, sosyal, kalite güvence ve üretim boyutlarını içeren sürdürülebilirlik konuları ele alınmıştır. Ayrıca salgın döneminde bu ana kriterlerin tedarik zincirine etkisini incelemek amacıyla detaylı araştırma yapılmıştır. Tedarik zincirinin karmaşık yapısında bir savunma sanayi şirketinin tedarikçi seçiminin çoklu kriterleri sürdürülebilirlik dahilinde ve şirket isteklerine uygun şekilde yapılması hedeflenmiştir. Önce literatür araştırması yapıldı. Sürdürülebilir tedarikçi seçimi kriterleri tespit edilmiştir. Sonrasında savunma sanayisinde üretim yapan bir ana sanayi firmasından seçilen karar vericilerden, bu araştırmanın uygulanması için belirlenmiş olan bütün kriterleri önceden belirlenmiş önemlerine görece değerlendirmeleri talep edilmiştir. Bu çalışma çerçevesinde tedarikçi seçimini etkileyen tüm kriterler sürdürülebilirlik başlığı ve ana sanayi isterleri yapısına uygun olacak şekilde belirlenmiştir. Önem dereceleri belirlenen kriterlerin Bulanık AHP yöntemi ile ağırlıkları belirlenmiştir. Sürdürülebilir tedarikçi kavramının tedarikçi seçimi süreçlerine dahil olmasıyla çevre, sosyal, kalite güvence, ekonomi ve üretim kriterleri kullanılarak tedarikçi seçimi yapılmıştır. Bu kapsamda çalışmanın belirlenen kriterlerin ağırlıklarının hesaplanmasında Bulanık AHP yöntemi kullanılmıştır. Alternatif seçiminde Bulanık EDAS ve Bulanık VIKOR yöntemleri kullanılarak bütünleşik birçok kriterli karar verme modeli oluşturulmuştur. Bu yöntemler açısından çalışmaya özgünlük katmıştır. Ayrıca 5 ana kategori olması ve 19 alt kriterden oluşması çok fazl kriter olması sebebiyle bir diğer özgünlük olmuştur.
Sonuçlar incelendiğinde firmanın çalıştığı aktif tedarikçilerin sıralamalarda ilk çıktığı gözlemlenmiştir. Karar vericilerin tutarlı olduğunun bir göstergesidir. Kullanılan iki yöntemde aynı alternatifin ilk çıkması yöntemlerin doğru uygulandığını göstermektedir. Farklı ÇKKV yönteminin kombinasyonu ve ele alınan çok sayıda alt ölçütlerin sürdürülebilirlik temalı olması, mevcut çalışmalara göre bu tez çalışmasını özgün ve kaliteli kılmaktadır. Kovid-19 döneminde tedarik zinciri yönetimi konularının araştırılması ve özgün analizler bu çalışmanın bir diğer literature katkısıdır.

Abstract:
The effective management of the supply chain has become a critical imperative for businesses, given its intricate structure and susceptibility to a myriad of factors and threats. The inherent complexities of supply chain management amplify the risks associated with any disruption within the chain. The advent of the COVID-19 pandemic, a global crisis that spread rapidly worldwide, underscored the vulnerabilities of the interconnected globalized world, resulting in widespread disruptions and significant delays in supply chains. The risk planning strategies, previously assigning a minimal probability, specifically less than 1%, to the occurrence of a pandemic before 2020, have undergone a profound reevaluation in light of the post-COVID-19 era now recognized as a high-risk period. This paradigm shift in risk perception has prompted businesses to reevaluate their strategies and adopt more resilient and adaptive approaches to supply chain management. Following the pandemic, a global chip crisis emerged as a consequence of an unprecedented surge in demand for microchips. This surge, coupled with sanctions, restrictions, and governmental challenges, particularly impacted the automotive industry. Projections indicate that by 2030, electronic components will constitute a staggering 45% of each automotive vehicle. The profound repercussions of the crisis in automotive factories manifested in widespread layoffs, triggering a social crisis with far-reaching implications.
The automotive industry, grappling with the chip crisis, found itself unable to meet the surging demand, resulting in a virtual sellout. High-tech vehicles, equipped with advanced technology, remained immobilized on factory floors as chipless or incomplete vehicles accumulated in storage areas, presenting a poignant symbol of the challenges faced by the industry. In response, supply chain managers are compelled to adopt proactive risk planning measures, conducting thorough examinations that seamlessly integrate the sustainability dimension into supplier selection and management, aiming to ensure resilience and continuity at every step of the chain. The emergence of disruptions in the supply chain is acknowledged as one of the foremost risks for businesses. In recent years, the sustainability approach within the supply chain has garnered significant importance as businesses recognize the need for a more holistic and forward-thinking strategy. An increasing number of companies are expanding their procedural frameworks and contractual obligations to encompass the entirety of the supply chain. This expansion aims to enhance supplier relationships, prolong the lifespan of suppliers, and identify potential risks well in advance, fostering a more sustainable and resilient supply chain.
Globally and domestically, leading companies are taking proactive steps by sequentially publishing sustainability principles, indicating their commitment to this cause by establishing dedicated departments. Stakeholders, including procurement teams, supply chain managers, academics, and individuals in pivotal roles, universally recognize the critical nature of supply chain management within the context ofsustainability in today's intensifying competitive landscape. This recognition has led to collaborative team formations and research endeavors, signifying a collective effort to address the evolving challenges in supply chain sustainability.
Businesses are actively exerting pressure on their sub-suppliers, encouraging all stakeholders within the supply chain to align with sustainability goals. The proactive planning for the needs of current generations while anticipating those of future generations is deemed crucial. Substantial efforts have been invested globally to address this issue, with a pressing imperative to utilize the limited physical resources of the economy and mitigate the resulting waste. The escalating global waste problem has transformed into a more significant issue, prompting governments to implement measures against the rapid consumption of the world's resources due to the burgeoning population of consumer societies. Expectations for a global ecological crisis have intensified, propelling a swifter pace in sustainability efforts across industries. The pressures exerted by major industries on their suppliers have contributed to heightened awareness among suppliers, fostering a collective commitment to sustainability practices. Concurrently, with the increasing consciousness of sustainability issues, supplier selection within supply chain management is no longer exclusively based on economic criteria. Instead, it is conducted holistically, considering environmental, social, economic, and quality aspects. An examination of contemporary sustainability practices reveals that supply chain management and its performance, coupled with sustainability, have become pivotal performance measurement criteria for companies.
The selection of suppliers based on sustainability criteria and the determination of their performance play a crucial role in shaping the landscape of modern supply chain management. This imperative has compelled suppliers to proactively undertake initiatives, not merely as a response to market demands but to avoid the apprehension of losing business in an era where sustainability is increasingly becoming synonymous with resilience and longevity.
This comprehensive study aims to refine the supplier selection process to align more closely with current conditions. It emphasizes the integration of the sustainability paradigm and adherence to objective values. Sustainability issues, spanning environmental, economic, social, quality assurance, and production dimensions, have been meticulously addressed to provide a robust framework for supplier selection. The study further delves into exhaustive research to investigate the impact of these primary criteria on the supply chain during the pandemic period, contributing valuable insights to the evolving field of supply chain management. In the intricate structure of the supply chain, the objective is to select suppliers for a defense industry company based on multiple criteria within the sustainability framework and in alignment with company requirements. The study employs a methodical approach, commencing with a comprehensive literature review to identify sustainable supplier selection criteria. Subsequently, decision-makers selected from a defense industry company are actively engaged to evaluate all predetermined criteria in terms of their relative importance for the implementation of this research.
Within the framework of this study, all criteria influencing supplier selection are meticulously ascertained to be conducive to sustainability and aligned with the core requirements of the main industry. The weights of the criteria, with assigned importance degrees, are determined with precision using the Fuzzy Analytic Hierarchy Process (AHP) method. The integration of the sustainable supplier concept into thesupplier selection process is a pivotal step, utilizing environmental, social, quality assurance, economic, and production criteria for supplier selection.
In this context, the Fuzzy AHP method is employed to calculate the weights of the identified criteria, ensuring a nuanced consideration of their relative importance. For alternative selection, both Fuzzy EDAS and Fuzzy VIKOR methods are judiciously applied. Upon scrutinizing the results, a notable observation is the high ranking of the active suppliers of the company, indicating a robust level of consistency among decision-makers. The fact that the same alternative consistently secures the top position in both methods serves as a testament to the accurate application of the methodologies employed. The amalgamation of diverse Fuzzy Multi-Criteria Decision-Making (MCDM) methods and the comprehensive emphasis on numerous sub-criteria related to sustainability distinguish this thesis, elevating its quality compared to existing studies. The original research and analyses of supply chain management issues during the COVID-19 period contribute significantly to the existing literature, providing a comprehensive and nuanced understanding of the challenges and opportunities in contemporary supply chain sustainability.