Elektrik sektöründe Edas ve Vikor yöntemi ile yeşil tedarikçi seçimi
Green supplier selection with Edas and Vikor methods in the electricity industry
Yazar: ÖZLEM KARATAŞ
Danışman: DR. ÖĞR. ÜYESİ TİJEN ÖVER ÖZÇELİK
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / Endüstri Mühendisliği Ana Bilim Dalı / Mühendislik Yönetimi Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: Endüstri ve Endüstri Mühendisliği = Industrial and Industrial Engineering
Dizin: EDAS = EDAS ; Elektrik sektörü = Electricity sector ; VIKOR yöntemi = VIKOR method ; Yeşil tedarik zinciri = Green supply chain ; Çok kriterli karar verme = Multi criteria decision making

Özet:
İşletmeler yıllarca zehirli sıvı, katı, gaz biçiminde atıklarla doğayı kirletmiş ve
yeryüzüne vermiş oldukları zararları hesaba katmamışlardır. Doğanın önemi ve
gözlenmesi bakış açısı 90'larda önem kazanarak gündeme gelmiştir. Çağımız, bu bakış
açısı ile doğaya daha farklı bir hassasiyetle yaklaşarak, işletmelerin endüstriyel
anlamında ilerlemelerine olanak sağlamaktadır. Bu sayede farklı alanlar da faaliyet
gösteren işletmeler doğayla dost nihai ürün üretilmesine destek olmaktadırlar. Aynı
zamanda, ürün yaşam döngüsünün her basamağında doğanın dengesini koruyarak
yeşil uygulamalarla gündeme gelmektedirler. Kağıt işletmelerinin üretilen kağıdı
tekrar kullanılabilir konuma getirmesi, plastik üretimi gerçekleştiren işletmelerin
çevreci hassasiyetle üretim yapmaları, bu alanda yapılan çalışmalardandır ve
günümüzde oldukça önemli uygulamalardır. Bu sektörler dışında da birçok işletme,
çevre dostu yaklaşımla üretim gerçekleştirmekte ve bu anlayışı tüm üretim süreçlerine
yansıtmaktadırlar. İşletmelerin bu çevre dostu üretim bakış açısında doğru yeşil
tedarikçi seçimi önemli bir yer tutmaktadır. Tüketicilerin de bu doğa dostu görüşe
sahip olması ve yapılan yasal planlamalar da işletmeleri yeşil tedarik zinciri
yaklaşımına yönelmektedir. Doğaya verilebilecek tehlikelerin en aza indirilme hedefi
yeşil tedarik zincirinin yönetim faaliyetlerinin etkinliğini arttırmaktadır.
Yeşil tedarik zinciri yönetiminde çevre ile ilgili yaklaşımların hedeflenmesi, onu
önemli bir noktaya taşımaktadır. Bu yaklaşımı benimseyen işletmeler; sahip oldukları
tedarikçilerinde ilerlemelerini en iyilemek için çok çeşitli hedefler belirleyerek bunları
tedarikçilerine sunmaktadırlar. Böylece işletmeler rakiplerini geride bırakabilecek
doğa dostu tedarikçilere sahip olmaktadırlar. Bu konu birçok işletmenin öncelikli
olarak gördükleri çalışmaların başında gelmektedir. Söz konusu çalışmaların
geliştirilmesi ve yürürlüğe konması maliyet bakımından işletmeleri zora
sokabilmektedir. Bu çalışmalar arasından en iyinin belirlenmesi ve bunun
uygulanabilmesi zorlu süreçlerden biridir. Aynı zamanda bilgi yetersizliği, yapılan
çalışmalarda arzu edilen hedeflerin tutturulamaması, işletmelerin altyapı sorunlarının
olması bazı sıkıntılar yaratabilmektedir.
İşletmeler, günümüz koşullarında birden fazla tedarikçiye sahip olmakta ve bunlar
arasından en iyisinin, en yeşil yaklaşıma sahip olanın seçimini gerçekleştirmek
durumda kalmaktadır. Bu durum da işletmeler için tedarikçi seçim/karar verme
problemlerini gündeme getirmekte ve bu problemler birçok belirsizlik
barındırmaktadır. Karar vericilerin kararlarını objektif, doğru olarak verebilmesi
özellikle de kriter ve alternatif sayılarının fazla olması durumunda daha da önem
kazanmaktadır. Bu durumda, çok kriterli karar verme yöntemleri, birden çok alternatif
ve kriter olması durumunda bilimsel ve sistematik bir yaklaşımla değerlendirmeyi
mümkün kılmaktadır. Bu özelliğinden dolayı yeşil tedarikçi seçim problemlerinde çok
yaygın olarak kullanılmaktadır. Çok kriterli karar verme teknikleri nicel bilgilerin
yetersizliğinin aşılmasını sağlamaktadır. Aynı zamanda bu teknikler konularında
uzman kişilerin fikirlerini temsil yeteneği açısından da güçlüdür. Bu bağlamda, yeşil
tedarikçi problemlerinde kazanç ve çevreci ölçütleri beraber ele alabilen bu teknikler
işletmeler için rekabet avantajı sunabilmektedir.
Bu çalışmaya konu olan, yeşil tedarikçi seçim çalışmasının gerçekleştirildiği
işletmede, hali hazırda RoHS analizi kullanılmaktadır. RoHS analizi ile işletme
tedarikçi seçimi yapmaktadır. Bu analiz tekniği ile civa, kadmiyum, kurşun, krom
değerleri olması gereken standart ölçüm değerleri ile kıyaslanıp analiz edilerek
tedarikçi seçimi gerçekleştirilmektedir. Tedarikçi seçimine temel olan kritik parça,
çalışmanın gerçekleştirildiği işletmede üretilen otomatik sigortalarda kullanılan
cıvatalardır. Bu kapsamda gerçekleştirilen çalışmada; çok kriterli karar verme
tekniklerinden olan EDAS ve VIKOR yöntemleri ayrı ayrı ele alınarak işletme için en
iyi yeşil tedarikçi seçimi yapılmış ve RoHS analizi ile tutarlılığı irdelenmiştir. Bu
amaçla öncelikle işletmedeki uzmanların görüşü ve literatürden elde edilen; uygunluk
kalitesi, yeşil ürün tasarımı, yeşil satınalma, yeşil üretim kriterler olarak belirlenmiştir.
Çok kriterli karar verme tekniklerinden olan EDAS ve VIKOR tekniği belirsizlik
altında karar vermede etkili ve karmaşık problemleri objektif bir yaklaşımla, hızlı bir
şekilde sonuca ulaştırdığı için tercih edilmiştir. RoHS analizi, çalışmada
gerçekleştirilen yeşil tedarikçi seçimi ile işletmenin mevcutta kullandığı tedarikçi
seçiminin geçerliliğinin kıyaslanması amacı ile kullanılmıştır.

Abstract:
For years, businesses have polluted nature with toxic liquid, solid and gaseous wastes
and have not considered the damage they have caused to the earth. The point of view
of the importance and observation of nature came to the fore by gaining importance in
the 90s. With this point of view, our age approaches nature with a different sensitivity,
allowing businesses to progress in an industrial sense. Today, businesses reveal their
primary purposes with this point of view. In this way, businesses operating in different
fields support producing environmentally friendly end products. At the same time, they
come to the fore with green practices by preserving the balance of nature at every step
of the product life cycle. Making the produced paper reusable by paper enterprises and
producing with environmental sensitivity by plastic production enterprises are studies
in this field and are very important applications today. Apart from these sectors, many
businesses carry out production with an environmentally friendly approach and reflect
this understanding in all production processes. Choosing the right green supplier is
essential in enterprises' environmentally friendly production perspective. Consumers
also have this nature-friendly view and the legal plans made are also turning businesses
towards the green supply chain approach. The aim of minimizing the dangers that can
be given to nature increases the efficiency of the management activities of the green
supply chain.
Targeting environmental approaches in green supply chain management takes it to an
important point. Businesses that adopt this approach; set a wide range of targets and
present them to their suppliers to optimize their progress in the suppliers they own.
Thus, businesses have eco-friendly suppliers that can leave their competitors behind.
This issue is at the forefront of the work that many businesses see as a priority. The
development and implementation of these studies can put businesses in difficulties in
terms of cost. One of the challenging processes is determining the best among these
studies and implementing it. At the same time, lack of information, failure to achieve
the desired targets in the studies, and the infrastructure problems of the enterprises can
create some problems.
In today's conditions, businesses have more than one supplier, and they must choose
the best one with the greenest approach. This situation raises supplier
selection/decision-making problems for businesses, which contain many uncertainties.
It becomes even more critical that decision-makers make their decisions objectively
and accurately, especially if the number of criteria and alternatives is high. In this case,
multi-criteria decision-making methods make it possible to evaluate with a scientific
and systematic approach in case of multiple alternatives and criteria. Due to this
feature, it is widely used in green supplier selection problems. Multi-criteria decisionmaking 
techniques enable us to overcome the inadequacy of quantitative information.
At the same time, these techniques are robust in representing the ideas of experts in
their fields. In this context, these techniques can handle profit and environmental
criteria together in green supplier problems and offer a competitive advantage for
businesses.
RoHS analysis is currently used in the enterprise, the subject of this study, where the
green supplier selection study is carried out. With the RoHS analysis, the company
chooses a green supplier. With this analysis technique, mercury, cadmium, lead, and
chromium values are compared and analyzed with the required standard measurement
values, and green supplier selection is made. The critical part, the basis for supplier
selection, is the bolts used in the automatic fuses produced in the enterprise where the
study is carried out. In the study carried out in this context, EDAS and VIKOR
methods, which are multi-criteria decision-making techniques, were handled
separately. The best green supplier was selected for the enterprise, and its consistency
with RoHS analysis was examined. For this purpose, firstly, the opinion of the experts
in the enterprise obtained from the literature, compliance quality, green product design,
green purchasing, and green production criteria were determined. EDAS and VIKOR
techniques, which are multi-criteria decision-making techniques, have been preferred
because they are influential in decision-making under uncertainty and provide a quick
solution to complex problems with an objective approach. The study used RoHS
analysis to test the validity of green supplier selection.
EDAS and VIKOR techniques, which are one of the multi-criteria decision making
techniques, are the most effective in decision making under uncertainty. These
techniques capture very complex problems quickly by filtering the appropriate step.
Multi-criteria decision-making is defined as the decision-making process in which the
purpose is evaluated for each option simultaneously in the decision-making process.
The biggest difficulty in this process is that an option achieves the optimum benefit in
terms of one criterion and cannot achieve the same (same) benefit in terms of another
criterion. It expresses a point of view based on the selection of the option in which all
the criteria provide maximum benefit. Multi-Criteria Decision Making (MCDM) deals
with the decision-making process influenced by many criteria. Multi-criteria decision
making; Multi-objective decision making is divided into two groups consisting of
multi-quality decision making. The two groups are generally considered in the same
sense. Whether the decision space is continuous or discrete is the determining factor
in these two groups. Problems in which the number of options are infinite become
multi-objective decision making problems. An example of this is mathematical
programming. Although multi-criteria decision-making methods have multiple and
different structures, some aspects are common. Alternatives, criteria, incomparable
units of measure, criterion weights, decision matrix constitute the common aspects of
multi-criteria decision making methods
In multi-criteria decision making methods, criteria are weighted. Different decisions
are made by weighting the criteria. In multi-criteria decision-making methods, weight
assignments should be made according to the criteria. It is a very rare event that all
criteria are evaluated with exactly the same measurement units in the decision-making
problem. The comparison of criteria for non-identical unit values is called the
normalization process .
In the literature, criteria weighting methods are considered subjectively and
objectively. Delphi is shown as an example of subjective methods. Objective methods,
on the other hand, can be described as Entropy Weighting Method, Importance
Determination of Criteria by Correlation between Criteria method or multi-objective
programming technique as models. In subjective methods, while the evaluation criteria
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are weighted according to the choices of the decision makers; In objective methods,
weighting is done according to real data. The common feature of all the methods is
based on the weighting process by using both the judgments of the decision makers
and the numerical information simultaneously. Multi-criteria decision making
problems are expressed in matrix form. In this matrix, alternatives, decision criteria,
weights of decision criteria are considered as the element of the matrix that expresses
the success of the alternative.
there are . Multi-criteria decision making methods are based on determining the
optimum choice and grouping the alternatives
There are many methods used in multi-criteria decision making in the literature. Many
methods have different features according to their structure. The methods used in
multi-criteria decision making are grouped as deterministic, stochastic and fuzzy
methods. Grouping process is done according to the type of data and the number of
decision makers, as single decision maker techniques and multiple decision maker
techniques .
The main methods used in multi-criteria decision making; Weighted Product Models
can be arranged as Analytical Hierarchy Process (AHP), Electre, Topsis, Promethee.
The Analytical Hierarchy Process (AHP) is a multi-criteria decision-making technique
developed through Saaty. The steps of the AHP method are defining the problem,
structuring the hierarchical order, creating binary comparison matrices for the criteria,
determining the importance levels of the criteria, measuring the consistency,
determining the importance levels of the alternatives according to each of the criteria,
and determining the percent importance of the alternatives .
The VIKOR method is a multi-criteria decision-making technique that obtains the
optimum ranking of options by utilizing criterion weights obtained by AHP or other
methods under agreed conditions. VIKOR, one of the multi-criteria decision-making
methods, aims to optimize multi-criteria decision systems and to provide maximum
group benefit. This method is a multi-criteria decision making method that uses each
value of the alternatives to achieve the most appropriate ranking. The VIKOR
technique aims to get closer to the optimum solution . It is used quite frequently in
many fields. The VIKOR method is mostly used in robot selection, water resources
planning, material selection and risk assessment . Many methods have been developed
to solve business problems. Solutions to single-objective decision making problems
are developed with linear and non-linear programming and integer programming.
Linear programming is the most widely used method. While it is the method applied
to solve the problems of the enterprises; The result it produces may not produce the
desired result with the production method. In the economic process, inputs and outputs
may conflict with indivisibility problems. Integer programming solves this division.
Integer linear programming model is a mathematical programming designed on the
basis that all parameters take non-negative integer values. In integer linear
programming, some or all of the variables take integer values .
There are some differences between linear programming model and integer
programming. In linear programming, decision parameters are required to be zero or
greater than zero. In integer programming, it is required that the decision variables take
a large integer value equal to zero.
Choosing the right supplier has an important place for businesses. With the right
supplier selection, businesses can find the opportunity to achieve successful service
quality. Production in companies consists of many rings. Another part of this ring is
suppliers. At this point, it reveals how influential the selection of suppliers is. In
particular, the fact that businesses can provide good quality service to their customers,
improve their process processes, reduce the raw material used in production and
production costs, is achieved by choosing the right supplier. Supplier companies that
are not selected optimally increase the process processes of the enterprises and cause
an increase in the time to respond to customer expectations. In addition, wrong supplier
selection creates serious financial losses for businesses.
A correct supplier must comply with the management principles of the enterprise.
Suppliers who are in constant communication with the enterprises respond to the
problems of the enterprises in a very short time. A consistent management structure of
the suppliers and at the same time their technology capacities must be developed.
RoHS analysis is currently used in the enterprise where this study is carried out. With
the RoHS analysis, the appropriate green supplier is selected on behalf of the
enterprise. At the same time, with this analysis technique; The mercury, cadmium,
lead, chromium values are compared and analyzed with the standard measurement
values, and the green supplier is selected. In the study, testing the validity of green
supplier selection was aimed with different techniques. For this purpose, firstly the
opinion of the experts in the enterprise and obtained from the literature; compliance
quality, green product design, green purchasing, green production criteria were
determined. EDAS and VIKOR methods, which are multi-criteria decision-making
techniques, were handled separately and the optimum green supplier was selected for
the enterprise and its consistency with RoHS analysis was examined.