LEE- İşletme Mühendisliği-Doktora
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Sustainable Development Goal "Goal 9: Industry, Innovation and Infrastructure" ile LEE- İşletme Mühendisliği-Doktora'a göz atma
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ÖgeDesigning business model framework for public bus transportation authorities: A fuzzy approach(Graduate School, 2023-02-22) Buran, Büşra ; Erçek, Mehmet ; 507162010 ; Management EngineeringCovid-19, which has taken the world under its influence, has also deeply affected the public transportation sector. While public transportation is sustainable with subsidies, the gap between expenses and incomes has grown with the effect of Covid-19. The sector, which meets the majority of its revenues from tickets, decreased by ninety percent during the days of curfews during the pandemic period. Expenses such as disinfection, mask, etc. increased with the addition of additional items. Despite all the difficulties, public transportation continued to serve without stopping during the pandemic period. For this reason, public transportation is seen as a backbone for the cities. Especially in developed and developing countries, it plays a critical role to overcome traffic jams. To achieve this, the service quality of public transportation is seen as a key point. The service quality of public transportation depends on different factors such as operation, repair and maintenance, audit, and management. From the management side, the business model provides a holistic perspective due to taking into account activity, value, and financial status. Business models represent a critical tool for strategic management. It provides managers with an integrated perspective to shape business operations regarding the activity, value, and finance dimensions. When activity composes of key partners, key resources, and key activities, value includes value proposition, customer segments, channels, and customer relationships. Lastly, the finance block comprises revenue streams and costs from Business Model Canvas (BMC) perspective. It serves to understand, communicate, share, change, measure, simulate, and learn more about the different aspects of the firms. According to the type of organization, the business model can be varied such as profit-based or social-based. This thesis presents a business model canvas framework for public transportation organizations including impact factors and their external environment. Impact factor includes social and environmental issues for public bus transportation such as elderly people, disabled people, electric buses, and green transportation. From an external view, PESTEL analysis is taken into account which is political, economical, social, technological, legal, and environmental. Taking into account impact factors and the external environment provides managers or policymakers with a holistic perspective to manage effectively. The main and sub-criteria of the model are designed according to the literature under three hierarchical levels. While the first level of the model is the main criteria which are internal and external environment criteria, the second level comprises sub-criteria of internal and external environment criteria which are business model canvas and PESTEL analysis. Finally, the third level is related to the sub-criteria of the business model and PESTEL analysis. In addition, this thesis aims to query the viability of a new strategic action tool specifically geared to the interests of public bus transportation authorities (PBTAs) around the globe and explore the degree of homogeneity in their responses as well as their possible drivers of them. To answer its research question, the study first offers a generic business model design for a PBTA, which integrates an extended version of the business model canvas with external environmental factors in order to enhance its sustainability. Subsequently, the importance attributions of international transportation experts to different model components are evaluated by using the Spherical and Intuitionistic Fuzzy AHP method. The proposed model is evaluated by experts from four continents: America, Asia, Australia, and Europe. International experts are selected according to their experience. They are selected from different departments which are planning, operation, innovation, strategy development, and finance with more than ten years of experience. There are different methods in the literature such as Multi-Attribute Utility Theory, Analytic Hierarchy Process (AHP), Analytic Network Process (ANP), Fuzzy Set Theory, Case-Based Reasoning, Data Envelopment Analysis, Simple Multi-Attribute Rating Technique, Goal Programming, Elimination and Choice Translating Reality (ELECTRE), Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), Simple Additive Weighting, Multicriteria Optimization and Com promise Solution (VIseKriterijumska Optimizacija I Kompromisno Resenje-VIKOR), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), and The Weighted Aggregated Sum Product Assessment (WASPAS). Analytic Hierarchy Process (AHP) is mostly used method due to its ease of application, flexibility, applicable to many subjects. But in some circumstances such as vagueness, complexity fuzzy logic is preferred to classical AHP. In fuzzy logic, there are different fuzzy sets. Some of those are Ordinary, Interval-Valued, Intuitionistic, Neutrosophic, Nonstationary, Hesitant, and Spherical. In this problem, fuzzy logic is applied to the model with two extensions which are Intuitionistic Fuzzy Sets (IFS) and Spherical Fuzzy Sets (SFS) to evaluate the proposed model. A solution set is also provided with a traditional AHP in order to check the robustness of the former methods. According to the results, the internal environment is ranked as the most important criterion at the first level for all methods. Whereas the activity element is ranked first at the second level, key partners are ranked first at the third level for all methods. The relative similarity of the results obtained by the traditional and Intuitionistic Fuzzy AHP model suggests that the Spherical Fuzzy AHP model may have better potential to handle the vagueness of the business modeling problems. Sensitivity analyses show that the model is sensitive to expert judgments. From the convergence-divergence perspective, the expert opinions tend to converge more on the internal components of the model and diverge on the external components, especially regarding economic and technological factors. A strategic response action set is also designed to facilitate the adoption of the model by PBTAs. The strategic responses include short and long terms actions, separately. When unexpected conditions such as pandemics trigger short-run responses, the long-run term is mobilized by the planning process. Innovation of the business model is important as designing it. Changing political, economical, social, technological, and legal conditions, the business models can be needed to redesign to survive in the business ecosystem. Development of the proposed business model can be tracked using defined performance indicators time by time. This study contributes to the works of both academicians and practitioners in terms of designing and evaluating public transportation business models. The study not only extends the research on the strategic management of the public bus transportation domain but also contributes to the convergence and divergence debate by offering a reconciliatory duality perspective.
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ÖgeEvolutionary mechanisms of imprinting in business clusters(Graduate School, 2021-03-10) Ekşi, Emre ; Erçek, Mehmet ; 507102006 ; Management Engineering ; İşletme MühendisliğiDiscussions on regional economic development, specifically on industrial districts and business clusters, since Marshall's (1920) seminal work has surged in numbers, especially after the popularization of cluster studies with Porter (1990), who assigns a prominent role to clusters in microeconomics of competition and competitive advantage of regions and nations. On the other hand, the geographic distribution of resources and potentials for development are shaped by historical factors and regions can be understood through the mechanisms by which geographical landscape evolves over time. In this sense 'Evolutionary turn' is both promising as a new way of thinking about uneven geographical development and presenting an opportunity for linking different concepts and theoretical approaches from different schools of thoughts. Aim of this thesis is to reveal how clusters evolve and in which conditions environmental forces leave their mark on the evolution pattern of business clusters. Instead of employing a nurturist view, this study explores how nature of the cluster firms and nurturing of the environment interact during the variations observed in environments and tries to explain the dynamics of the imprinting processes. Even though spatial evolution of business clusters has been studied in business history and economic geography domains, coherent and holistic view of the phenomenon is still far from formulation. Contribution of this study is to bring an evolutionary model by extending multi-level imprinting theory (MLIT) with a selectionist view and to explain how particular features of business clusters are acquired under the influences of environmental forces. The study, in so doing, synthesizes MLIT and General Darwinism, which are built over analogies between evolutionary biology and evolutionary economic geography and lay the foundation of the basic evolutionary engine as variation, selection and retention processes. The thesis consists of seven sections. In the first section, aim and scope of the thesis is presented, and the flow of the thesis is framed. In the second section, theoretical perspectives on location, regional growth and local development are discussed, theoretical background of business clusters is summarized. In the third section the importance of 'Evolutionary turn' is highlighted, the concepts of evolutionary analysis within the economic landscape are discussed and imprinting theory is presented. In the fourth section, the conceptual model, explaining evolutionary mechanisms of imprinting and how environmental influencers work with evolutionary engine is described, evidences from the empirical literature are presented. In the fifth section, research design is explained, selection of sites and how data are collected and analyzed is justified. In the sixth section, findings related to footwear industry and footwear production clusters in Izmir and Konya are presented. In the last section findings are discussed in the light of conceptual model, how evolutionary mechanisms and engine explain the imprinting success or failure is presented, and new research opportunities for developing the model are offered. The proposed conceptual model aims to contribute to the evolutionary economic geography by extending MLIT in many ways; (i) exploring influence of heredity factors governing access to resources and legitimization forces, (ii) defining how "window of imprintability" works through evolutionary mechanisms, (iii) explaining emulation of imprints through retention process and the role of secondhand imprinting, (iv) describing the role of pioneering firms in the creating founder effect and lastly, (v) clarifying the role of institutional order within group of firms as a constraining factor with its implications on the imprinting process. This study follows a historical case study research which is suitable for exploring the cluster as a contextually bounded system over time. The research setting planned for this study is footwear clusters which is a traditional industry, geographically agglomerated and based on apprenticeship. Before preparing the research questions a preliminary site research is conducted and discussions with highly experienced professionals are made. This also enabled the researcher to be more informed about the research sites in Konya and Izmir. Interview questions were determined after the preliminary site research and compiled in accordance with the conceptual model and its constructs. Data collected by open-ended interviews are triangulated with other secondary data sources like sectoral reports, journals, academic papers and studies, archival records, photograph archives, direct observation and physical artifacts. In the study, data analysis is conducted in four stages. In the first stage background of shoe production in Turkey is explained and current context is clarified with historical facts and figures. In the second stage, sensitive periods related to major economical, technological and institutional changes are investigated. In the third stage, selected areas to be analyzed are justified. In the last stage, imprinting process and their action mechanisms are deeply investigated. Possible imprints on specialization, division of work and cooperation are analyzed, and findings are interpreted according to the conceptual approach. Findings towards specialization showed that the specialization of Izmir footwear cluster in women shoes was affiliated with Westernization efforts in which shoe consumption habits were shaped by liberalized clothing, social life and attendance of women in work life. On the other hand, this WOI did not turn automatically into an imprint. The environmental fit of producers shaped by the local demand enabled them to seize this opportunity and retention was mainly characterized by apprenticeship and spin-offs, which pushed the imprints to stamp a critical mass of the population. Findings in division of work uncovered three cases for deeper analysis. In the case of stitcheries, small stitching workshops found to be sustained since the traditional production era despite the change in the economic conditions. These workshops persisted and attempts to replace this model failed due to unregistered work practices and traditionalization forces of within group fitness, characterized by irregular working hours, seasonality and underdeveloped managerial capacities. These findings showed the importance of both environmental fitness and within group fitness in the imprinting process. The case of Sumerbank was an example of Wrightian-drift. During state led industrialization period, Turkish Republic founded Sumerbank and consolidated all state production facilities including the shoe factory in Beykoz, which was a vertical production giant of its time. The favorable selection niche created by the government did not breed into new mass production facilities and transform into a successful imprint on the industry. The barriers blocking diffusion of vertical production model seems not only to indicate the lack of capital accumulation of producers but also presence of a parallel fit in the crossing niche and lack of physical proximity disabling knowledge dissemination. Moreover, the sensitive period characterized by state led development logic closed in less than two decades. Therefore, retention mechanism did not work, and imprinting attempt was failed. On the contrarily, the socialist imprint in Timişoara footwear cluster which was coeval with the Sumerbank initiative had successfully persisted even after the firms were privatized. This points attention to the importance of retention mechanism and reaching a critical threshold for solidification and persistence of the imprint. Lastly, findings on the Ottoman guilds and their Akhsim roots, which are mostly referred in the discussions of collaboration efforts in Konya, showed that both functions and values possessed by the ancestor of modern collaboration institutions have been mostly vanished. In this sense three sensitive periods are analyzed, foundation period, industrialization and mechanization with liberalization. The evidence supports the view that with the upsurge in competition, individualistic behavior has intensified, and individual fit became more important than group fit after the liberalization and mechanization period. Our conceptual model supports us to propose that liberalization changed the course of social norms and relations and this may lead to an imprint in the future. These findings contributed to the imprinting theory by highlighting the importance of the nature of business clusters, incorporation of a selectionist view and evolutionary mechanisms. The accumulated heredity factors and window of imprintability operating in the imprinting process are both conceptually and empirically explained. Sensitive periods do not automatically result in the evolution of a cluster. Instead, the model affirms that during a sensitive period, the operations in the variation-selection-retention engine, overcoming the pressures of within group fitness and reaching a critical mass in the local populations are prerequisites for successful imprinting.
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ÖgeInternet of things and digital transformation (industry 4.0) strategy and benefits for manufacturing firms(Graduate School, 2022-05-24) Ömerali, Mete ; Kaya, Tolga ; 507172008 ; Management EngineeringThe world is changing faster than ever before. Previous industrial revolutions happened within an average of hundred years. The first industrial revolution of mechanization happened in the 18th century followed by electrification in the early 20th century and automation happened towards the end of the 20th century as well. Only after a quarter of a century, the last and fourth industrial revolution kicked in. Digitalization is the key trend of the Industry 4.0 revolution. One of the key aspects of digitalization brought by Industry 4.0 is driven by the Internet of Things. Industrial companies are transforming the way they design and maintain their products, solutions, and production capabilities. Consumer requirements became more demanding than ever before. Competition among the manufacturing companies is at its limits and transforms the products to be more complex. Yet, other challenges such as faster time to market, higher quality needs, and regulations and legislation force enterprises to provide new ways of designing, manufacturing, and servicing their end products. Such changes do not happen overnight, the transformation within large organizations are key aspects of their survival. Because of that, firms are collecting lots of information before deciding on their strategies for digital transformation. One key problem in this regard is to decide on either to buy or implement (vertical integration) such technologies objectively and efficiently. Many firms are dependent on a few individuals' decision-making capabilities. However, human decision-making is not objective most times and this could cause issues for the firms to make the best decision. This thesis consists of three published articles that focus on the 4th industrial revolution's effect on digital transformation strategies and benefits for manufacturing firms. As well as providing a strategical roadmap throughout the journey of digital transformation. Multi-criteria decision-making is key for firms to determine the most appropriate solution among a large set of alternatives. To overcome subjective human judgment challenges, the fuzzy multi-criteria decision-making frameworks are introduced in each article. The proposed frameworks aim to help manufacturing firms strategically apply digital transformation. The first article defines a fuzzy framework for the manufacturing firms in their investment decision in the internet of things domain. From the two possibilities of internal make decision vs external buy decision, there are many factors to be considered. The detailed literature review indicates six important criteria for manufacturing firms to consider in their transformation journey decision making. Based on the provided decision criteria, the Type-2 Fuzzy COPRAS method is used as an application of the framework to help manufacturing organizations compare available alternatives and decide for their organizational nature. The suggested framework is tested in an industrial case study and findings are discussed in the paper. The results indicate that digital transformation is preferred to be outsourced due to its complex nature. In the second article, based on the approach provided by the first article, one of the key components of digitalization is applied. The article investigates how the manufacturing firms should decide on which Product Lifecycle Management (PLM) solution to buy from available options based on the enterprise's requirements. In order to identify the key criteria for PLM selection, a detailed literature analysis is conducted. The result of the literature review shows that six very important criteria exist for PLM application selection. Furthermore, to reduce subjective human judgment, the interval-valued Spherical Fuzzy COPRAS method is suggested as an application selection framework. The industrial case study is applied and alternative PLM solutions are ranked for the case-studied manufacturing firms. The results were satisfactory for the decision-making firms and the proposed framework was considered to be successful by them. In the third and last article, based on the findings from the first article and similarly to the second article, an Augmented Reality (AR) application selection framework is proposed. AR applications are taking a key part in the digital transformation of manufacturing firms. The detailed literature review suggests nine very important criteria to be used to compare alternative AR solutions. To reduce subjective human judgment, the Spherical Fuzzy COPRAS multi-criteria decision-making framework is proposed. The suggested method is tested in an illustrative example and findings are shared with sensitivity analysis. As a result, the thesis provides a strategical roadmap for manufacturing firms to apply digital transformation using internet of things concepts in the era of the 4th industrial revolution. Provided fuzzy COPRAS multi-criteria decision-making frameworks help firms to reduce human judgment subjectivity in their decision making. Furthermore, the detailed literature reviews identify the key criteria for selection frameworks to help manufacturing firms to gain time and conduct best in class decision-making.
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ÖgeTalep tahmini için gri temelli bir yaklaşım(Lisansüstü Eğitim Enstitüsü, 2022-01-11) Bilgiç Tanyolaç, Ceyda ; Çebi, Ferhan ; 507122001 ; İşletme MühendisliğiGri sistem teorisi ilk olarak 1989 yılında literatüre kazandırılmış bir çalışma alanıdır. Gri sistem teorisinin alt konularından biri olan gri tahmin ise, bu tez çalışmasının da temelini oluşturmaktadır. Talep tahmini çalışmaları literatürde sıklıkla karşılaşılan alanlardan olup, bu çalışmada talep tahmini için gri tahmin modellerinden yararlanılmıştır.Talep tahmininde ise enerji ve dolayısıyla elektrik talebi (tüketimi) tahmini çalışmaları günümüzde önem arz etmektedir. Kapasitenin doğru planlanması ve doğru fiyatlandırılma politikası, doğru tüketim tahminleriyle başarılı olacaktır. Tüm bu durumlardan yola çıkarak; bu tez çalışmasının temel amacı, talep tahmini için yeni bir model sunmaktır. Bu çalışmada gri modelin küçük boyutlu verilerle yapılan tahminlerde başarılı olmasının avantajına odaklanarak hata oranını daha da küçükleyecek melez modeller sunmak amaçlanmıştır. Tezde elektrik tüketimi tahmini üzerine yapılan uygulamada kullanılan ve önerilen modeller, literatürde ilk kez kullanılan hibrit modellerdir. Bu yönüyle çalışma literatüre önemli katkı sağlamaktadır. Literatür taraması ile gri tahmin modeller kullanılarak yapılan tahmin çalışmaları ve alanları, elektrik tüketim tahmininde kullanılan gri modeller ve Türkiye'de yapılan elektrik tüketimi tahmin çalışmalarında kullanılan modeller genel olarak incelenmiş ve bu bilgiler ışığında hibrit bir model olan bulanık GM (1,1) parametre optimizasyonu Güve- Işık Optimizasyonu Algoritması modeli önerilmiştir. Önerilen bu modele yuvarlanma mekanizması da eklenerek bir model önerisinde daha bulunulmuştur.Yapılan literatür taramasında gri modellerde parametre optimizasyonu çalışmaları da incelenmiş ve sıklıkla kullanılan metasezgisellerin olduğu çalışmalara yer verilmiştir. Çalışmada literatür taraması ve talep tahmini konusundan sonra literatürde en çok kullanılan Gri modellere ve bu tezin temel modeli olan Üçgen Bulanık GM(1,1) modeline detaylı biçimde yer verilmiştir. Sonrasında ise; metasezgisel algoritmalar konusu incelenmiş ve parametre optimizasyonunda kullanılan metasezgiseller detaylıca anlatılmıştır. Önerilen modellerin denklemleri ayrıntılı bir şekilde ifade edilmiş ve Türkiye'nin kısa dönem elektrik tüketimi tahmini konusunda bir çalışma yapılarak sonuçlar yorumlanmıştır. Uygulama, MATLAB 2018b programından yararlanılarak yapılmıştır. Önerilen modeller literatürde var olan gri model ile kıyaslanarak tahmin performansı başarımı ölçülmüştür. Kullanılan hata ölçütü literatürde sıklıkla kullanılan Ortalama Mutlak Yüzde Hatası (OMYH)'dır. Modellerde kullanılan ve literatürde yeni olan Güve- Işık Optimizasyonu Algoritması'nın performansı ise literatürde parametre optimizasyonu için sıklıkla kullanılan algoritmalarla kıyaslanarak ölçülmüştür. Söz konusu algoritma ile önerilen modeller Genetik Algoritma ile kıyaslandığında daha iyi bir tahmin performansı sergilemekte olup; PSO ile kıyaslandığında en az onun kadar güçlü olduğu sonucuna varılmıştır. Kıyaslama yapılırken programın çalışma süresi ve metasezgisellerin optimum noktayı yakaladıkları iterasyon sayıları dikkate alınmıştır. Uygulama sonuçlarına bakıldığında önerilen modellerin tahmin performansının geliştiği gözlemlenmiştir. GIOA, Genetik Algoritmaya göre süreler ve iterasyon sayıları açısından çok daha iyi sonuç verirken; PSO ile kıyaslandığında ise yakın süreler ve iterasyon sayıları vermekte olduğu gözlemlenmiştir. Son olarak, yapılan araştırma ve edinilen bilgiler ışığında tez çalışmasının sonuçları yorumlanmış ve gelecek çalışmalarla ilgili önerilerde bulunulmuştur.