Aytac Yildiz - Academia.edu (original) (raw)
Papers by Aytac Yildiz
2013 IEEE INISTA, 2013
ABSTRACT White goods brand selection decision have become a multi-criteria decision making proble... more ABSTRACT White goods brand selection decision have become a multi-criteria decision making problem depending on the variety of customer demands and developments at the white goods technology recently. In this study, the selection of the best among the alternative white goods brand is handled as a Multi Criteria Decision Making (MCDM) problem. Within the scope of this study, alternative three white goods brands (A, B, C) are evaluated. Firstly in the scope of the evaluation, a decision team is created as formed by two persons from three families who confronted with such kind of a choice problem. Common view of the decision team is taken for generating hierarchical decision model to be used in evaluation of alternative white goods brands. The Generalized Choquet Integral (GCI) method, being one of the MCDM methods, is used at solution of the problem. At the end of the study, obtained results and evaluations are included.
Hata Turu ve Etkileri Analizi (HTEA) sistematik bir analiz yontemi de olsa hata turlerini degerle... more Hata Turu ve Etkileri Analizi (HTEA) sistematik bir analiz yontemi de olsa hata turlerini degerlendiren kisilerin subjektif ifadelerine dayanmasi sebebiyle ayni zamanda sezgisel de bir yontemdir. Sezgilere dayanmasi ise uygulamada bazi eksikliklere ve kisitlamalara yol acmaktadir. Bu problemleri ortadan kaldirabilmek icin yontemi cok kriterli karar verme yontemlerinden biri olan gri iliskisel analizi ile birlikte kullanmak, sezgisel durumlari ortadan kaldirarak onlem alinmasini ve duzeltilmesi gereken hata turlerinin onceliklendirilmesini saglamaktadir. Bu calismada bugday eleme makinesi uretimindeki hatalarin tespit edilerek onceliklendirilmesi ve alinacak onlemlerin belirlenmesi icin klasik HTEA ve gri iliskisel analizi ile butunlestirilmis HTEA yaklasimlari uygulanarak yaklasimlarin etkinligi degerlendirilmistir. Bunun icin ilk once klasik HTEA ile Risk Oncelik Sayilari (ROS) daha sonra ise gri iliskisel analizi ile butunlestirilmis HTEA yaklasimiyla risk faktorlerinin hem esit a...
Sanayi sektoru, gerek yuksek enerji tasarruf potansiyeline sahip olmasi, gerekse de sanayide tuke... more Sanayi sektoru, gerek yuksek enerji tasarruf potansiyeline sahip olmasi, gerekse de sanayide tuketilen enerjinin cogunlukla ticari enerji olmasi nedeniyle enerji tasarrufu calismalarinda oncelikle ele alinmasi gereken bir sektordur. Turkiye’de birincil enerjinin %24’unu, elektrigin ise %47’sini sanayi sektoru kullanmaktadir. Ulkemiz sanayisi agirlikli olarak emek ve enerji yogun alanlarda varlik gostermeye calistigindan dolayi OECD ulkeleri icinde enerji yogunlugu yuksek ulkelerin basinda gelmektedir. Bu ise isletmeleri diger ulkelerdeki isletmelerle rekabet etmesi anlaminda zor durumda birakmaktadir. Bu yuzden ustun nitelikli ana uretim prosesleri-teknolojileri, bu teknolojileri destekleyen atik isi geri kazanimi, kompenzasyon, otomasyon gibi destekleyici teknolojiler ve verimlilik felsefesi ile orulmus enerji yonetim anlayisinin benimsenmesi gerekmektedir. Bu baglamda sanayide enerji verimliligini artirmak icin, enerji muhasebesi, kontrol sistemleri, yalitim, yeni teknolojiler ve ...
IŞLETMELERIN HIZMET KALITESI PERFORMANSININ DEĞERLENDIRILMESINE ILIŞKIN BIR KALITE FONKSIYONU GOC... more IŞLETMELERIN HIZMET KALITESI PERFORMANSININ DEĞERLENDIRILMESINE ILIŞKIN BIR KALITE FONKSIYONU GOCERIMI UYGULAMASI
Sakarya University Journal of Science
Modern sanayi gelişimi birkaç yüz yıldır sürmüş ve günümüze gelinceye kadar üç büyük sanayi devri... more Modern sanayi gelişimi birkaç yüz yıldır sürmüş ve günümüze gelinceye kadar üç büyük sanayi devrimi ortaya çıkmıştır. Şu an ise Endüstri 4.0 olarak adlandırılan dördüncü sanayi devrimine girilmiştir. Endüstri 4.0, birbirleriyle haberleşen, sensörlerle ortamı algılayabilen ve veri analizi yaparak ihtiyaçları fark edebilen robotlarla üretimi devralıp; daha kaliteli, daha ucuz, daha hızlı ve daha az israf yapan bir üretim yapmayı amaçlamaktadır. Ayrıca, Endüstri 4.0, modüler yapılı akıllı fabrikalarda siber fiziksel sistemler ile fiziksel işlemleri izleyerek nesnelerin birbirleriyle ve insanlarla iletişime geçmesine izin verir ve bunun sonucu olarak merkezi olmayan işbirlikçi kararların verilmesini sağlar. Günümüzdeki rekabet ortamında işletmelerin varlıklarını koruyabilmeleri ve sürdürebilmeleri için Endüstri 4.0'ı organizasyonlarına uygulaması kaçınılmaz olmuştur. Bunun için de Endüstri 4.0 kavramının ve temel olan paradigmalarının çok iyi bilinmesi gerekmektedir. Bundan dolayı bu çalışmada, Endüstri 4.0 ve temel paradigmaları açıklanmış, akıllı fabrikalar hakkında bilgi verilerek genel bir değerlendirme yapılmıştır.
Project team consisting of members from various departments, is called project development team o... more Project team consisting of members from various departments, is called project development team or cross functional team. These teams enhance success by making quick decisions and finding solutions to problems encountered. Within the enterprise, effective communication between members, development of motivation and the support of top management improve the success of these teams. Accordingly, product quality is enhanced; customer satisfaction and efficiency are improved. In the context of this study, a field research covering 52 companies operating in ceramic industry has been carried out. Data obtained as a result of field research were assessed using statistical program SPSS 15.0. Within the scope of assessment, factor analysis, reliability analysis, correlation and regression analysis were made. When the analysis findings were examined, a positive relation between the organizational features of establishment (support of top management, communication and motivation) and the succes...
In the last 20 years, rapid and significant developments have occurred in communication and infor... more In the last 20 years, rapid and significant developments have occurred in communication and information technologies. In parallel with these developments, the importance of smartphones has increased. In addition, many smartphone manufacturers have launched and continue to launch a number of new models with many features. People who want to buy a new smartphone have difficulties selecting the best smartphone among the numerous models available on the technology markets. Therefore, smartphone selection has become a complex multi-criteria decision-making (MCDM) problem for people. Hence, decision-making processes will be facilitated by using MCDM methods, and these will provide the most appropriate decision. In this paper, the best smartphone among the 28 alternatives determined by the person who will buy them are selected by using three main criteria and 17 sub-criteria with the help of a two-phased MCDM approach. In the first phase, 28 smartphone alternatives are ranked using the ana...
Bu calismada, otomotiv yan sanayiinde faaliyet gosteren firmalarda, urun gelistirme ekip yapisini... more Bu calismada, otomotiv yan sanayiinde faaliyet gosteren firmalarda, urun gelistirme ekip yapisinin urun gelistirme performansi uzerindeki etkilerini ortaya koyabilmek amaciyla bir anket calismasi yapilmistir. Arastirma verilerinin elde edilmesi amaciyla hazirlanan anket, Istanbul ve Gebze’de faaliyet gosteren orta ve buyuk olcekli 51 firmaya uygulanmistir. Anketten elde edilen veriler SPSS istatistik programinda faktor, guvenilirlik, korelasyon ve regresyon analizi ile degerlendirilmistir. Elde edilen sonuclara gore, urun gelistirme ekibinin yapisinin bilesenleri olan; capraz fonksiyonel ekipler, ekip uyelerinin ortak konumlandirilmasi, yetkilendirilmis ekip ve ekip kararliliginin, urun gelistirme performansini pozitif yonde ve anlamli bir sekilde etkiledigi gorulmustur.
Sakarya Universitesi Fen Bilimleri Enstitusu Dergisi, 2013
In today's world where intensive competition exists between enterprises, it is of great im-po... more In today's world where intensive competition exists between enterprises, it is of great im-portance to work in cooperation with the right suppliers. Selection of the right suppliers is a significant factor in the success of enterprises. In the selection of the best supplier (s), the strengths and weaknesses of potential suppliers should be taken into consideration. Many qualitative and quantitative criteria are included in this selection process as well as the decision-maker. One of the issues that leaves the decision maker in a difficult position is selecting the most appropriate one from the alternatives available, as traditional methods may not produce a realistic solution in this process. However, multicriteria decision making methods facilitate the process of finding a solution and enable decision makers to reach the right decisions. In this study, the fuzzy TOPSIS method, which is one of the multi-criteria decision making methods, is used in this problem area to select the...
Decision Science Letters, 2017
Supplier selection is a complex multi-criteria decision making (MCDM) problem. There are literall... more Supplier selection is a complex multi-criteria decision making (MCDM) problem. There are literally various methods for choosing appropriate supplier but there are several criteria involved in complex decision making process. The classical MCDM methods cannot effectively solve real-world problems however fuzzy MCDM methods facilitate the solution fairly and enable the decision-makers to reach accurate decisions in this selection process. In this study, a supplier selection problem is handled, in a firm in automotive industry of Turkey. Fuzzy TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) and generalized Choquet integral are used individually in the solution of the problem.
South African Journal of Industrial Engineering
A firm's multi-criteria decision-making (MCDM) process is important because of its need to select... more A firm's multi-criteria decision-making (MCDM) process is important because of its need to select and work with various suppliers. The process identifies the problems associated with selecting the supplier, , determining convenient criteria, expressing interactions clearly, and usage. These are all suitable methods for finding a solution to these MCDM problems. Considering more than one criterion (and even the sub-criteria of these criteria) during supplier selection makes the selection uncertain. Conventional methods cannot generate a realistic solution to the problem. Using MCDM methods considerably simplifies solving the problem, and enables decision-makers to make better decisions. In this study, a literature review was performed on MCDM methods used between 2001 and 2014 for the supplier selection problem. MCDM methods used in supplier selection are categorised into three main methods, and a summary table of the reviewed studies is presented.
The South African Journal of Industrial Engineering, 2013
Nowadays, in parallel with the advancing technology, automobiles that have substantially advanced... more Nowadays, in parallel with the advancing technology, automobiles that have substantially advanced technological properties are being manufactured. Intended uses of the automobiles have been changing in our days in contrast to 1960s when automobiles were only used for transportation. Consumers, in our day and age, expect profoundly different properties from an automobile. In this context, more than one criterion become effective on making decision on purchasing an automobile that has the required properties. In such a kind of decision problem, making use of Multi Criteria Decision Making (MCDM) methods will ease the solution of the problem and will enable the decision makers to make right decisions. In this study, fuzzy Analytic Network Process (ANP) method, one of the MCDM methods, is used in automobile purchasing decision making. After determining decision criteria and alternatives, network structure of the automobile selection decision problem is formed, and by using fuzzy ANP method, the best one is selected among three alternative automobiles that are in the same segment and are very approximate to each other in terms of their properties and prices.
2013 IEEE INISTA, 2013
ABSTRACT White goods brand selection decision have become a multi-criteria decision making proble... more ABSTRACT White goods brand selection decision have become a multi-criteria decision making problem depending on the variety of customer demands and developments at the white goods technology recently. In this study, the selection of the best among the alternative white goods brand is handled as a Multi Criteria Decision Making (MCDM) problem. Within the scope of this study, alternative three white goods brands (A, B, C) are evaluated. Firstly in the scope of the evaluation, a decision team is created as formed by two persons from three families who confronted with such kind of a choice problem. Common view of the decision team is taken for generating hierarchical decision model to be used in evaluation of alternative white goods brands. The Generalized Choquet Integral (GCI) method, being one of the MCDM methods, is used at solution of the problem. At the end of the study, obtained results and evaluations are included.
Hata Turu ve Etkileri Analizi (HTEA) sistematik bir analiz yontemi de olsa hata turlerini degerle... more Hata Turu ve Etkileri Analizi (HTEA) sistematik bir analiz yontemi de olsa hata turlerini degerlendiren kisilerin subjektif ifadelerine dayanmasi sebebiyle ayni zamanda sezgisel de bir yontemdir. Sezgilere dayanmasi ise uygulamada bazi eksikliklere ve kisitlamalara yol acmaktadir. Bu problemleri ortadan kaldirabilmek icin yontemi cok kriterli karar verme yontemlerinden biri olan gri iliskisel analizi ile birlikte kullanmak, sezgisel durumlari ortadan kaldirarak onlem alinmasini ve duzeltilmesi gereken hata turlerinin onceliklendirilmesini saglamaktadir. Bu calismada bugday eleme makinesi uretimindeki hatalarin tespit edilerek onceliklendirilmesi ve alinacak onlemlerin belirlenmesi icin klasik HTEA ve gri iliskisel analizi ile butunlestirilmis HTEA yaklasimlari uygulanarak yaklasimlarin etkinligi degerlendirilmistir. Bunun icin ilk once klasik HTEA ile Risk Oncelik Sayilari (ROS) daha sonra ise gri iliskisel analizi ile butunlestirilmis HTEA yaklasimiyla risk faktorlerinin hem esit a...
Sanayi sektoru, gerek yuksek enerji tasarruf potansiyeline sahip olmasi, gerekse de sanayide tuke... more Sanayi sektoru, gerek yuksek enerji tasarruf potansiyeline sahip olmasi, gerekse de sanayide tuketilen enerjinin cogunlukla ticari enerji olmasi nedeniyle enerji tasarrufu calismalarinda oncelikle ele alinmasi gereken bir sektordur. Turkiye’de birincil enerjinin %24’unu, elektrigin ise %47’sini sanayi sektoru kullanmaktadir. Ulkemiz sanayisi agirlikli olarak emek ve enerji yogun alanlarda varlik gostermeye calistigindan dolayi OECD ulkeleri icinde enerji yogunlugu yuksek ulkelerin basinda gelmektedir. Bu ise isletmeleri diger ulkelerdeki isletmelerle rekabet etmesi anlaminda zor durumda birakmaktadir. Bu yuzden ustun nitelikli ana uretim prosesleri-teknolojileri, bu teknolojileri destekleyen atik isi geri kazanimi, kompenzasyon, otomasyon gibi destekleyici teknolojiler ve verimlilik felsefesi ile orulmus enerji yonetim anlayisinin benimsenmesi gerekmektedir. Bu baglamda sanayide enerji verimliligini artirmak icin, enerji muhasebesi, kontrol sistemleri, yalitim, yeni teknolojiler ve ...
IŞLETMELERIN HIZMET KALITESI PERFORMANSININ DEĞERLENDIRILMESINE ILIŞKIN BIR KALITE FONKSIYONU GOC... more IŞLETMELERIN HIZMET KALITESI PERFORMANSININ DEĞERLENDIRILMESINE ILIŞKIN BIR KALITE FONKSIYONU GOCERIMI UYGULAMASI
Sakarya University Journal of Science
Modern sanayi gelişimi birkaç yüz yıldır sürmüş ve günümüze gelinceye kadar üç büyük sanayi devri... more Modern sanayi gelişimi birkaç yüz yıldır sürmüş ve günümüze gelinceye kadar üç büyük sanayi devrimi ortaya çıkmıştır. Şu an ise Endüstri 4.0 olarak adlandırılan dördüncü sanayi devrimine girilmiştir. Endüstri 4.0, birbirleriyle haberleşen, sensörlerle ortamı algılayabilen ve veri analizi yaparak ihtiyaçları fark edebilen robotlarla üretimi devralıp; daha kaliteli, daha ucuz, daha hızlı ve daha az israf yapan bir üretim yapmayı amaçlamaktadır. Ayrıca, Endüstri 4.0, modüler yapılı akıllı fabrikalarda siber fiziksel sistemler ile fiziksel işlemleri izleyerek nesnelerin birbirleriyle ve insanlarla iletişime geçmesine izin verir ve bunun sonucu olarak merkezi olmayan işbirlikçi kararların verilmesini sağlar. Günümüzdeki rekabet ortamında işletmelerin varlıklarını koruyabilmeleri ve sürdürebilmeleri için Endüstri 4.0'ı organizasyonlarına uygulaması kaçınılmaz olmuştur. Bunun için de Endüstri 4.0 kavramının ve temel olan paradigmalarının çok iyi bilinmesi gerekmektedir. Bundan dolayı bu çalışmada, Endüstri 4.0 ve temel paradigmaları açıklanmış, akıllı fabrikalar hakkında bilgi verilerek genel bir değerlendirme yapılmıştır.
Project team consisting of members from various departments, is called project development team o... more Project team consisting of members from various departments, is called project development team or cross functional team. These teams enhance success by making quick decisions and finding solutions to problems encountered. Within the enterprise, effective communication between members, development of motivation and the support of top management improve the success of these teams. Accordingly, product quality is enhanced; customer satisfaction and efficiency are improved. In the context of this study, a field research covering 52 companies operating in ceramic industry has been carried out. Data obtained as a result of field research were assessed using statistical program SPSS 15.0. Within the scope of assessment, factor analysis, reliability analysis, correlation and regression analysis were made. When the analysis findings were examined, a positive relation between the organizational features of establishment (support of top management, communication and motivation) and the succes...
In the last 20 years, rapid and significant developments have occurred in communication and infor... more In the last 20 years, rapid and significant developments have occurred in communication and information technologies. In parallel with these developments, the importance of smartphones has increased. In addition, many smartphone manufacturers have launched and continue to launch a number of new models with many features. People who want to buy a new smartphone have difficulties selecting the best smartphone among the numerous models available on the technology markets. Therefore, smartphone selection has become a complex multi-criteria decision-making (MCDM) problem for people. Hence, decision-making processes will be facilitated by using MCDM methods, and these will provide the most appropriate decision. In this paper, the best smartphone among the 28 alternatives determined by the person who will buy them are selected by using three main criteria and 17 sub-criteria with the help of a two-phased MCDM approach. In the first phase, 28 smartphone alternatives are ranked using the ana...
Bu calismada, otomotiv yan sanayiinde faaliyet gosteren firmalarda, urun gelistirme ekip yapisini... more Bu calismada, otomotiv yan sanayiinde faaliyet gosteren firmalarda, urun gelistirme ekip yapisinin urun gelistirme performansi uzerindeki etkilerini ortaya koyabilmek amaciyla bir anket calismasi yapilmistir. Arastirma verilerinin elde edilmesi amaciyla hazirlanan anket, Istanbul ve Gebze’de faaliyet gosteren orta ve buyuk olcekli 51 firmaya uygulanmistir. Anketten elde edilen veriler SPSS istatistik programinda faktor, guvenilirlik, korelasyon ve regresyon analizi ile degerlendirilmistir. Elde edilen sonuclara gore, urun gelistirme ekibinin yapisinin bilesenleri olan; capraz fonksiyonel ekipler, ekip uyelerinin ortak konumlandirilmasi, yetkilendirilmis ekip ve ekip kararliliginin, urun gelistirme performansini pozitif yonde ve anlamli bir sekilde etkiledigi gorulmustur.
Sakarya Universitesi Fen Bilimleri Enstitusu Dergisi, 2013
In today's world where intensive competition exists between enterprises, it is of great im-po... more In today's world where intensive competition exists between enterprises, it is of great im-portance to work in cooperation with the right suppliers. Selection of the right suppliers is a significant factor in the success of enterprises. In the selection of the best supplier (s), the strengths and weaknesses of potential suppliers should be taken into consideration. Many qualitative and quantitative criteria are included in this selection process as well as the decision-maker. One of the issues that leaves the decision maker in a difficult position is selecting the most appropriate one from the alternatives available, as traditional methods may not produce a realistic solution in this process. However, multicriteria decision making methods facilitate the process of finding a solution and enable decision makers to reach the right decisions. In this study, the fuzzy TOPSIS method, which is one of the multi-criteria decision making methods, is used in this problem area to select the...
Decision Science Letters, 2017
Supplier selection is a complex multi-criteria decision making (MCDM) problem. There are literall... more Supplier selection is a complex multi-criteria decision making (MCDM) problem. There are literally various methods for choosing appropriate supplier but there are several criteria involved in complex decision making process. The classical MCDM methods cannot effectively solve real-world problems however fuzzy MCDM methods facilitate the solution fairly and enable the decision-makers to reach accurate decisions in this selection process. In this study, a supplier selection problem is handled, in a firm in automotive industry of Turkey. Fuzzy TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) and generalized Choquet integral are used individually in the solution of the problem.
South African Journal of Industrial Engineering
A firm's multi-criteria decision-making (MCDM) process is important because of its need to select... more A firm's multi-criteria decision-making (MCDM) process is important because of its need to select and work with various suppliers. The process identifies the problems associated with selecting the supplier, , determining convenient criteria, expressing interactions clearly, and usage. These are all suitable methods for finding a solution to these MCDM problems. Considering more than one criterion (and even the sub-criteria of these criteria) during supplier selection makes the selection uncertain. Conventional methods cannot generate a realistic solution to the problem. Using MCDM methods considerably simplifies solving the problem, and enables decision-makers to make better decisions. In this study, a literature review was performed on MCDM methods used between 2001 and 2014 for the supplier selection problem. MCDM methods used in supplier selection are categorised into three main methods, and a summary table of the reviewed studies is presented.
The South African Journal of Industrial Engineering, 2013
Nowadays, in parallel with the advancing technology, automobiles that have substantially advanced... more Nowadays, in parallel with the advancing technology, automobiles that have substantially advanced technological properties are being manufactured. Intended uses of the automobiles have been changing in our days in contrast to 1960s when automobiles were only used for transportation. Consumers, in our day and age, expect profoundly different properties from an automobile. In this context, more than one criterion become effective on making decision on purchasing an automobile that has the required properties. In such a kind of decision problem, making use of Multi Criteria Decision Making (MCDM) methods will ease the solution of the problem and will enable the decision makers to make right decisions. In this study, fuzzy Analytic Network Process (ANP) method, one of the MCDM methods, is used in automobile purchasing decision making. After determining decision criteria and alternatives, network structure of the automobile selection decision problem is formed, and by using fuzzy ANP method, the best one is selected among three alternative automobiles that are in the same segment and are very approximate to each other in terms of their properties and prices.