Mühendislik Fakültesi, Endüstri Mühendisliği (İngilizce Destekli) Bölümü Koleksiyonu
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Güncel Gönderiler
Öğe Bankacılık sektöründe süreç madenciliği uygulamaları ve süreçlere etkilerinin Monte Carlo yöntemiyle incelenmesi(İstanbul Ticaret Üniversitesi, 2025) Mamuş Yemen, Rabia; Borat, OğuzBu çalışmada süreç madenciliği ile ilgili genel bilgiler verilmiş olup, bankacılık sektöründe faaliyet gösteren bir bankanın nakit çekme süreç verileri kullanılarak süreç madenciliği uygulaması yapılmıştır. Uygulama ile süreçte bulunan dar boğazlar tespit edilmiştir. Bu dar boğazların süreçten kaldırılması ile işlemlerin daha kısa zamanda yapılabileceği beklenmektedir. Bunu kantitatif olarak göstermek için bir bankanın 22 şubesinin bir yıllık ortalama işlem süreleri günlük işlemler, müşteriler, işlem sayıları ve ortalama süreleri modellenmiş ve günlük işlemler Monte Carlo yöntemi ile stokastik olarak simüle edilmiştir. Süreç madenciliğine dayanan dar boğazların kaldırılma etkisi modele uygulanmış ve süreç madenciliği uygulaması ile günlük işlem süresinin azaldığı nicel olarak gösterilmiştir. Sonuç olarak süreç madenciliği yazılımlarının bankacılık sektöründe kullanımı ile süreç geliştirme çalışmalarında iyileştirmeler yapılabilecektir.Öğe İstatistiksel süreç kontrolü teknikleri üzerine bir parfüm üretim hattında örnek uygulama çalışması(İstanbul Ticaret Üniversitesi, 2025) Güzel, Berk Kemal; Köksal, Mustafaİstatistiksel Süreç Kontrolü (İSK), mevcut sürecin izlenmesine ve iyileştirme çalışmalarının yürütülmesine imkan tanır. Süreçteki arızaların ve hataların tespiti ve çözümü için çetele, gruplandırma, Pareto analizi, histogram, balık kılçığı diyagramı, serpilme (korelasyon) ve kontrol diyagramları gibi yedi temel teknik kullanılır. Bu çalışmada, kozmetik sektöründe çeşitli kategorilerde ürünlerin üretimini gerçekleştiren bir işletmenin parfüm üretim hattında İSK tekniklerinin uygulanması incelenmiştir. İyileştirme çalışmalarına başlamadan önce, işleri kolaylaştırmak amacıyla parfüm hattının genel kuşbakışı çizimi ve iş akış diyagramı hazırlanmıştır. Ardından, üretim sürecinde ortaya çıkan arıza tiplerinin ve sebeplerinin belirlenmesi için düzenli veri toplama amacıyla çetele oluşturulmuştur. Öncelikli arıza nedenlerine odaklanmak için Pareto analizi yapılmıştır. İşletmede, arızaların başlıca nedenlerini belirlemek için balık kılçığı diyagramı oluşturulmuştur. Arıza sayısının dağılımının normal olup olmadığını kontrol etmek için histogram kullanılmıştır ve en sık tekrar eden hata tipleri arasındaki etkileşimi belirlemek için korelasyon diyagramları oluşturulmuştur. Sürecin kontrol altında olup olmadığını belirlemek için çetele tablosundan elde edilen verilerle kusurlu ürün yüzdeleri için p kontrol diyagramı oluşturulmuştur.Öğe A study on the importance of agile scalability in engineering management and its effect on high-tech exports in OECD(2020) Onur, Akif; Ekmekçi, İsmailAs a new world order is formed, entrepreneurial teams and engineering aproaches with small but quick and can mobilize collectively, reaching customers without extending market access time, are preferred instead of the traditional project method. Despite these preferences, the number of leaders in academia and business who adapt into the concept of agile engineering teams recently has been steadily decreasing. The study consists the literature review on introduction, the definition of the model which the criteria are shared in and the result stage and explains the relationship of R&D expenses from national income in OECD countries and the patent numbers of engineering management information systems, teams with the concept of agile models.Öğe Reverse logistics in the electronics waste industry(IGI Global, 2019) Ayvaz, Berk; Görener, AliRecently, due to the rapid world population growth, decreasing of natural resources and raw materials, increasing environmental awareness, interesting for wasting raw materials, using produced products more efficiently, and reusing of sources is rapidly increasing. Nowadays, reverse logistics as an important business strategy for profitable and sustainability is becoming important. The effective implementation of reverse logistics gives companies a competitive advantage in sectors. Due to mentioned reasons firms intend to incorporate reverse logistics activities such as the recovery, remanufacturing, recycling or disposal. Reverse logistics has become increasingly important as a profitable and sustainable business strategy. Therefore, more and more manufacturers have adapted the practice of recovering value from returned products and integrate product recovery activities into their processes. The electronic industry is one of the fastest growing manufacturing industries and the main purpose of this chapter is to explore the opportunities for waste returns within this sector.Öğe Assessment of environmental performance of ports utilizing an integrated LBWA-MARCOS decision-making approach based on picture fuzzy sets(Springer Science and Business Media Deutschland GmbH, 2024) Tatar, Veysel; Ayvaz, BerkThe management of a port is of critical economic significance because of its part in global trade. However, the expansion of port operations and the continued use of antiquated methods of labor have resulted in detrimental effects on the environment, thereby posing challenges to sustainability of ports. In order for ports to compete in the global market and to ensure customer satisfaction, the importance that port managers attach to environmental indicators comes to the fore. In this context, this study suggests a fuzzy integrated MCDM strategy that combines the picture fuzzy LBWA (PF-LBWA) and picture fuzzy MARCOS (PF-MARCOS) approaches in order to achieve this goal. The proposed model is also demonstrated through environmental performance analysis of ten major ports in Türkiye. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Öğe Gamma-neutron shielding parameters of (S3Sb2)x(S2Ge)100_x chalcogenide glasses nanocomposite(Pergamon-Elsevier Science Ltd, 2023) Şengül, Aycan; Akhtar, M. Shaheer; Akkurt, İskender; Malidarre, Roya Boodaghi; Er, Zuhal; Ekmekçi, İsmailIn the purpose of radiation shielding, (S3Sb2)x(S2Ge)100_x (x symbolscript 15, 30, 45 and 60 mol%) chalcogenide glasses were surveyed in the current study. The shielding achievements of the glass samples were investigated by using Phy-X/PSD simulation codes. This is done in terms of (LAC, mu, cm_1) for four different samples. Further, other essential parameters such as HVL, and neutron removal cross section were also calculated. These parameters were also tested with variation of SbS concentration in samples.Öğe Fault diagnosis on bottle filling plant using genetic-based neural network(Elsevier Sci Ltd, 2011) Demetgül, M.; Ünal, M.; Tansel, I. N.; Yazıcıoğlu, OsmanTimely detection of the pneumatic system problems is important in industry. Many techniques have been employed to solve this problem. In this paper, Genetic Algorithm (GA) based optimal configuration of neural networks is proposed for fault diagnostic of bottle filling systems. Back-propagation is used for neural networks algorithm. The back-propagation algorithm had six inputs and one output. A fitness function was designed to the minimize execution time of ANN model by keeping the number of hidden layer(s) and nodes as low as possible while the mean square error of estimated output error is minimized. The designed GA-ANN combination and the graphical user interface (GUI) eliminate the trial and error process for selection of the fastest and most accurate configuration. The performance of the proposed system was evaluated by using experimental data collected at a pneumatic work cell which attach caps to the bottles. The sensory data was collected at normal operating conditions and a series of faults were imposed to the system such as missing bottle, attaching nonworking bottle caps at two different cylinders, two air pressure problems (insufficient and low air), and not filling water. The study demonstrated the convenience, accuracy and speed of the proposed GA-NN environment. It may also be used for training for selection of ANN configurations at various applications. (C) 2011 Elsevier Ltd. All rights reserved.Öğe Digital transformation in the defense industry: A maturity model combining SF-AHP and SF-TODIM approaches(Elsevier, 2023) Nebati, Emine Elif; Ayvaz, Berk; Kuşakcı, Ali OsmanAs an inevitable process, digitalization has become a priority for many companies. The measurement of digital maturity is the first step toward adequately executing this. Although digital maturity models (DMM) have been developed for different sectors in the literature, such studies in the defense industry are lacking due to sector-specific dynamics. This study aims to close this gap and proposes a digital maturity model specific to the defense industry. In this study, a novel model was developed that combines the SF-AHP and SF-TODIM methods due to the uncertainty and hesitancy contained in the evaluation. The validity of the presented novel model has been demonstrated in a prominent defense company in Turkey. According to the results, the most notable digital maturity dimensions are the evaluation of opportunities and alignment with stakeholders. In addition, the model indicates that the company owns the required soft skills, such as leadership, organizational culture, and strategic determination for digital transformation (DT). On the other hand, essential hard skills such as technology and operational competencies are yet to be improved. Lastly, sensitivity and comparison analyses are conducted to validate and verify the obtained results' stability and robustness.Öğe Isparta ilinde bulunan bir kamu kuruluşuna AHP ve TOPSİS yöntemlerini kullanarak masaüstü bilgisayar seçimi(İstanbul Ticaret Üniversitesi, 2021) Doğan, Yılmaz; Borat, OğuzBu çalışmada Isparta ilinde bulunan bir kamu kuruluşunda kullanılmak maksadıyla masaüstü bilgisayar seçimi problemi ele alınmıştır. Çok kriterli karar verme yöntemlerinden AHP ve TOPSIS yöntemleri bir arada kullanılmış ve kurum için en ideal bilgisayar seçiminin yapılması amacıyla uygulanmıştır. Literatür incelendiğinde ve uzman personel ile yapılan görüşmeler neticesinde işlemci hızı, ram kapasitesi, garanti süresi, sabit disk kapasitesi, maliyet ve Isparta ilindeki servis ağı sayısı olmak üzere toplam 6 kriter tanımlanmıştır. AHP yöntemi kriterlerin ağırlıklarının belirlenmesinde, TOPSIS yöntemi ise alternatiflerin sıralanması amacı ile kullanılmıştır. AHP ve TOPSIS yöntemlerinin aşamaları MS Excel programı kullanılarak hesaplanmıştır. Çalışma sonucunda belirlenen alternatifler arasından en ideal masaüstü bilgisayar seçilmiştir.Öğe Designing reverse logistics network for end-of-life vehicles: A sustainability perspective in a fragile supply chain(2021) Ayvaz, Berk; Kuşakçı, Ali Osman; Aydın, Nezir; Ertaş, EmineEnvironmental guidelines in the automotive industry greatly emphasize the recycling, remanufacturing, and recovering of end-of-life vehicles (ELVs). Given the principle of extended producer responsibility, developing an effective reverse logistics network is the most significant digit ahead of the industry. However, initial attempts addressing the reverse logistics network design (RLND) problem were short-sighted, focusing on cost minimization. Undoubtedly, the whole concept of recycling was founded on the pillars of sustainability. Accordingly, reverse logistics network design must be motivated by long-term environmental and societal benefits. This fact has become even more prominent in the current pandemic environment as COVID-19 has added serious uncertainties and risks to the supply chain processes. This paper reiterates the essence of sustainability goals and proposes a multi-objective fuzzy mathematical model to RLND problem for ELVs under such a fragile and fuzzy environment. The coverage of the proposed model is to optimally determine the locations and numbers of the facilities and the flows among them concerning environmental, social, and economic aspects. Hence, the model aims to reach a robust compromise solution that leads to a resilient network design. A real case study on the ELV market in Istanbul/Turkey proves the merit of the developed model.Öğe Selection of alternative fuel taxis: A hybridized approach of life cycle sustainability assessment and multi-criteria decision making with neutrosophic sets(Taylor & Francis Online, 2021) Aboushaqra, Nour N. M.; Onat, Nuri Cihat; Kucukvar, Murat; Hamouda, A.M.S.; Kuşakçı, Ali Osman; Ayvaz, BerkThis study presents a combined application of hybrid life cycle sustainability assessment and multi-criteria decision-making, aiming to further advance an integrated sustainability assessment and decision-making for the selection of alternative-fuel taxis. First, a multiregional hybrid life cycle sustainability assessment model is built to evaluate macro-level sustainability impacts of various vehicle types: conventional gasoline vehicles, compressed natural gas vehicles, hybrid, and battery electric vehicles. Second, considering the subjective nature of the evaluation process, the intervalvalued neutrosophic sets-based analytic hierarchy process is suggested to assess the results obtained from the life cycle model to determine the weight of each evaluation criterion. Then, the technique for order preference by similarity to the ideal solution is used to rank the sustainability performance. Two different charging scenarios are also tested. The results show that solar-powered BEVs are the best in the environmental impacts with the exceptions of water consumption and land use. Solar-powered BEVs are superior in human health impact, while, ICVs are the best in compensation and employment generations. The ranking results reveal that solar-powered BEVs are the best alternatives when all indicators are considered, followed by CNG vehicles. The proposed method provides a practical and life cycle-based decision-making approach to support and prioritize effective policies for more sustainable transportation.Öğe Bitkisel tarım etkinliğinin veri zarflama analizi ile ölçümü: Türkiye’de il düzeyinde bir çalışma(İstanbul Ticaret Üniversitesi, 2021) Işık Aydın, Betül; Borat, OğuzVeri Zarflama Analizi; etkinlik, verimlilik veya performans terimlerinin hızla önem kazandığı her alanda akla gelen ilk yöntemlerden biridir. Bu makalede, tarım sektöründe Veri Zarflama Analizi (VZA) kullanılarak 2019 yılına ait etkinlik ölçümü yapılmıştır. Çalışmada Türkiye’de bitkisel üretim hasılası yüksek olan 20 il ele alınmıştır. Girdi olarak ‘İşlenen Tarım Alanı’, ‘Tarımsal Mekanizasyon’, ‘Tarımsal Sulamada Kullanılan Enerji’ ve ‘Gübre Tüketimi’ verileri kullanılmıştır. Çıktı olarak ise ‘Sebze Meyve Üretim’ ve ‘Tahıl ve Diğer Bitkisel Üretim’ verileri kullanılmıştır. Sonuca göre; CCR Model çözümünde 11 tane il ‘etkin’, 9 tane il ‘etkinsiz’, BCC Model çözümünde ise 10 tane il ‘etkin’, 10 tane il ise ‘etkinsiz’ bulunmuştur. Çalışmanın sonuç bölümünde illerin etkinlikleri karşılaştırılarak yorumlanmış ve performans iyileştirmeleri yapılmıştır.Öğe Risk assessment of corona virus: Implementing hierarchy of hazard control in workplaces(Peertechz Publications, 2021) Yıldırım, Fatma Demircan; Ekmekçi, İsmailThe novel coronavirus or the other name Severe Acute Respiratory Syndrome coronavirus-2 (SARS-CoV-2), was fi rst identifi ed in Wuhan, China, in December 2019 among a group of patients that have the same symtoms of viral pneumonia. Due to the socio-economic factors in Zhuhai, Wuhan and globalization have also accelerated the spread of infectious diseases to the other parts of China and the world [1,2], The World Health Organisation (WHO) declared Covid-19 a public health emergency of international concern as of 1 February 2020 and epidemic as pandemic on 12 March 2020. The virus spreads very rapidly and globally, as of 25 February 2021, there have been more than 113 million confi rmed cases of Covid-19, including more than 2.5 million deaths, reported to WHO. Although initation of vaccination have raised hopes of bringing the pandemic under control, the recent news about the mutated variant of the novel coronavirus associated with recent infections make governments and people concerned about the future. WHO is warning that back to old normals is likely to take a long time, possibly several years due to the time required to manufacture and distribute millions of doses of vaccine.Öğe Ömrünü tamamlamış araçların geri kazanımı için belirsizlik altında ağ tasarımı(Haliç Üniversitesi, 2020) Erdoğan, Duygu; Ayvaz, BerkDünya genelinde doğal kaynakların küçümsenemeyecek boyutlarda tükenmeye başlaması ve yenilenebilmenin mümkün olmadığı bu zamanda, en ufak bir ürünün geri dönüşümünün çevresel faydası çok fazladır. Ömrünü tamamlamış araçların (ÖTA) geri kazanımı çevresel faydasının yanı sıra, içerdikleri geri dönüştürülebilir malzemeler nedeniyle ekonomik faydasıyla da dikkat çeken önemli kaynaklardır. Bu çalışmada, ÖTA için açık döngü tersine lojistik ağ tasarım problemi ele alınmıştır. Ele alınan problemi modellemek için ilk aşamada ağdaki tüm parametreler belirli olarak kabul edilip karma tam sayılı doğrusal programlama modeli geliştirilmiştir. İkinci aşamada ise son kullanıcılardan gelen ömrünü tamamlamış araçların miktarı belirsiz olarak kabul edilip deterministik model iki aşamalı stokastik programlama modeli olarak genişletilmiştir. İlk aşamada model söküm tesisleri ve işleme tesislerinin açılması gibi stratejik kararlar alınmıştır. Stokastik modelin ikinci aşamasında ise modele belirsizlik dahil edilerek toplama maliyetleri, taşıma maliyetleri, işleme maliyetleri gibi kararlar alınmıştır. Geliştirilen her iki modelin uygulaması Türkiye’nin Ankara ilinde yapılmış ve sonuçlar değerlendirilmiştir.Öğe A Fuzzy integer programming model to locate temporary medical facilities as part of pre-disaster management(IGI Global, 2019) Ayvaz, Berk; Kuşakçı, Ali OsmanThe number and the scale of natural disasters have drastically increased over the last decades. One of the most vital stages of disaster preparedness is disaster response planning, and it plays an important role in limiting material and immaterial consequences, such as those caused by large scale earthquakes. In order to minimize human suffering and death, the aim of establishing a well-designed humanitarian relief chain must be to provide medicine, water, shelter, emergency food and supplies to the affected areas. From a holistic perspective, providing timely first aid and rapid transfer of injured victims to a medical facility is one of the most essential component of such chain. Thus, the location of first aid hospitals must be determined following a careful thought and planning process. This study presents a fuzzy integer programming model to determine the best location of the temporary hospitals which are expected to support extant state hospitals after a major earthquake. This study applies the proposed fuzzy model to the Üsküdar province of Istanbul and identifies optimum number and locations of field hospitals for a severe earthquake scenario.Öğe Type-2 fuzzy TOPSIS model for green third party logistics provider performance evaluation(International University of Sarajevo, 2019) Atasever, C.; Ayvaz, BerkABSTRACT: Green supplier selection, along with the environmental dimension in the supply chain, has attracted great interest both in the academic and institutional framework however, the supplier selection as well as the evaluation the performance of the current supplier affects the performance of the company and is important. In the real life, uncertainties in decision integral part of this process. are things that exist in the nature of decision making. Fuzzy set theory with the linguistic preferences was used to transform subjective decision-maker perceptions into a tangible net value. In this paper, it is proposed an interval type-2 fuzzy TOPSIS approach for green performance evaluation in GSCM. Then, it is applied in the performance evaluati Party Logistics (3PL) providers to validate the presented model.Öğe Biyoyakıt tedarik zinciri ağ tasarımı çalışmaları için öz düzenleyici haritalar(Süleyman Demirel Üniversitesi, 2020) Öztürk, Fatih; Kuşakçı, Ali Osman; Ayvaz, Berk; Sırakaya Karakoç, MelikeSon yıllarda çevre dostu yenilenebilir enerji kaynaklarına ilgi artmaktadır. Ülkemizde Enerji Piyasası Düzenleme Kurumu (EPDK) tarafından, 2013 yılından itibaren benzine ve motorine yerli katkı olarak, oranları her yıl arttırılmak üzere biyodizel ve etanol ilave zorunluluğu getirilmiştir. Bu da yenilenebilir enerji kaynakları için etkin ve optimal yeşil tedarik zinciri ağı tasarımı çalışmalarının yapılmasını gerekli kılmaktadır. Bu bağlamda karar vericiler, ekonomik gelişme sağlayan, çevre hassasiyeti olan ve sosyal refahı sağlayan sürdürülebilir çözümler üretmek için biyoenerji, rüzgâr, güneş, dalga, gelgit vs. gibi yenilenebilir enerjilere odaklanmışlardır Bu çalışmada biyoyakıtların tedarik zinciri ağ tasarımları ile ilgili yapılmış geçmiş çalışmalara yer verilmiş ve çalışmalar; amaçları, karar değişkenleri, kısıtları, kullanılan optimizasyon metodu ve sonuçları açısından analiz edilerek değerlendirilmiştir. İncelenen çalışmalar, yapay sinir ağlarının özel bir çeşidi olan öz düzenleyici haritalar (Self Organizing Maps-SOM) yöntemi kullanılarak kümelenmiş ve literatürdeki boşluklar tartışılmıştır. Literatürün incelemesi ve çalışmaların kümelenmesini içeren bu makale, biyoyakıt tedarik zinciri ağ tasarımı ile ilgili çalışma yapacak araştırmacılar için yol gösterici niteliktedir.Öğe Risk assessment and mitigation for unmanned aerial vehicles(M. B. Mondal, 2020) Yazıcıoğlu, Osman; Borat, OğuzUAVs performance is improved, in addition to GPS, they can find routes with artificial intelligence and various techniques, and can fly autonomously. The global UAV market was US$ 25.59 billion in 2018. It is estimated that the market will reach US$70.28 billion by 2029. The first three UAV manufacturers were DCL (USA), Parrot (France) and Yuneec (PRC) and are now being produced in many countries. Aircrafts are exposed to various risks: an aerodynamic stall due to inconsistent sensor readings and inadequate response, hitting a flock of geese or flying objects, pilot being unable to prevent the plane repeatedly nosediving despite following procedures. Therefore, procedures issued by aviation agency for aircraft type certification require an aircraft manufacturer (“applicant”) to demonstrate that its design complies with all applicable agency’s regulations and requirements. Safety risk management is a key component of a safety management system and involves fundamental activities such as identifying safety hazards, and assessing the risks and mitigation. Risk management is an integral component of safety management and involves some essential steps.Take into account any current mitigation measures and assess the seriousness in terms of the worst possible realistic scenario. The risk assessment considered five operational environments; remote, rural, suburban, urban, and congested. Reliability, availability, maintainability, and safety assessment are important study in the development of UAVs. This kind of study is mandatory to increase the reliability of the UAV, its availability, and to reduce repair and maintenance costs.Öğe Thermal optimization of partitioned electric water heaters for energy conservation(Ms. M. B. Mondal, 2020) Kar, A.K.; Yazicioglu, R.; Yazıcıoğlu, O.Optimum design and selection of storage type electric water heaters were analyzed for energy conservation. The thermal performance of a single tank electric water heater is compared with that of partitioned electric water heater for the same average domestic hourly hot water use pattern according to Becker’s profile. Both water heaters have the same volume capacity and total power rating while the temperature of the hot water was kept between 60 and 65oC. It is concluded that a partitioned electric water heater provides more hot water and reduces energy consumption whereas the upper part of the tank has 25% of the total volume and 75% of the total power rating. To evaluate single tank and partitioned electric water heaters transient energy balance equations have been derived and solved. Some assumptions made and thermodynamic properties received to use the evaluate differential equations. To represent water heater models equations required data obtained from literature.Öğe Efficiency and productivity analysis in Turkish banking sector with data envelopment analysis and malmquist index(International University of Sarajevo, 2020) Balcı, Emine; Ayvaz, BerkABSTRACT: The aim of this study is to analyze the efficiency and productivity of 3 public, 6 private and 6 foreign deposit banks operating in the Turkish banking sector with the help of data envelopment analysis and Malmquist index.For this purpose, the efficiency of 15 deposit banks operating in the Turkish banking sector between 2014 and 2018 was measured and whether the efficiency of Malmquist productivity index changed over the years. input-oriented Charnes Cooper and Rhodes (CCR) model was used under the assumption of constant return to scale and 4 input 2 output variables were selected. Inputs in efficiency and productivity measurement are defined as; personnel expenses / total assets (%), total loans / total assets (%), equity / total assets (%), total deposits / total assets (%), outputs are defined as; the earning power of assets (net profit / total assets), the earning power of equity (net profit / equity) (%). The Windows Data Envelopment Analysis Program package program was used in the analysis and brokerage approach was adopted. While 4 banks were active under the Constant Return to between 2014 and 2018, 8 banks were found active under the assumption of Variable Return to Scale (VRS).Inefficient banks; target values were calculated by slacks movement and radial movement values to their original values and it was found that the lambda values calculated by Win4Deap program and which banks are peers. The changes observed in Malmquist total factor productivity, technical efficiency, technological efficiency, pure efficiency, scale efficiency and total factor productivity were analyzed as a whole and decision experienced improvement in the 2016-2017 period.
