Computer Engineering / Bilgisayar Mühendisliği

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Now showing 1 - 10 of 18
  • Conference Object
    Citation - WoS: 3
    Citation - Scopus: 4
    Mikroservisler için İşgücü Kestirimi: Bir Durum Çalışması
    (IEEE, 2021) Ünlü, Hüseyin; Hacaloğlu, Tuna; Leblebici, Onur; Demirörs, Onur
    Software size measurement is critical as an input to perform important project management processes such as effort, cost and schedule estimation. Functional size measurement (FSM) methods are beneficial in terms of being applicable in the early phases of the software life cycle over functional requirements and providing a systematic and repeatable method. However, in agile organizations, it can be challenging to seperate measurement components of FSM methods from requirements in the early phases as the documentation is kept to a minimum compared to traditional methods such as the Waterfall Model and is detailed as the project steps. In addition, the existing FSM methods are not fully compatible with today's architectural structures, which are from being data-driven and to evolve into a behaviour-oriented structure. In this study, we performed a case study which includes a project developed with agile methods and using microservice-based architecture to compare the effectiveness of COSMIC FSM and event-based software size measurement. For this purpose, we measured the size of the project and created effort estimation models based on two methods. The measurers had difficulty in applying both methods due to the limited detail level of the requirements in the project. However, the event-based method was found to estimate effort with less error than the COSMIC FSM method.
  • Article
    Türkiye’deki Yazılım Organizasyonlarının Mikroservis Tabanlı Mimaride Uyguladığı Analiz ve Tasarım Yöntemleri Üzerine Bir Araştırma
    (TMMOB Elektrik Mühendisleri Odası, 2021) Ünlü, Hüseyin; Bilgin, Burak; Demirörs, Onur
    Günümüzde esnek, güvenilir ve duyarlı (responsive) yazılımlara olan talebin artması ve bu talebe karşılık verebilen internet altyapısının olması yeni nesil bulut uygulamalarının gelişmesine öncülük etmiştir. Bunun sonucunda, bulut tabanlı dağıtık web uygulamalarının birlikte çalışarak oluşturduğu mikroservis tabanlı mimari popülerlik kazanmıştır. Mikroservis tabanlı mimari oldukça yeni olup bu mimariyi kullanarak yazılım geliştiren firmaların kültürlerini değiştirme gerekliliği doğmuştur. Ancak, literatürde mikroservis tabanlı mimaride analiz ve tasarım konusunda uygulanan yöntemleri ele alan çalışma sayısı çok azdır. Bu çalışmada, Türkiye’deki yazılım organizasyonlarının mikroservis tabanlı proje geliştirirken başvurdukları analiz ve tasarım yöntemlerini ele alan bir anket düzenlenmiştir. Anket sonuçları, mikroservis tabanlı proje konusunda tecrübesi olan yazılım organizasyonlarının analiz ve tasarım konusundaki bakış açılarını ortaya çıkarmaktadır. Elde edilen sonuçlar mikroservis kullanan organizasyonlar ile ilgili genel tabloyu göstermekte ve araştırmacılar için çalışma yapılabilecek konuları önermektedir.
  • Conference Object
    Citation - WoS: 4
    Citation - Scopus: 12
    Event Oriented Vs Object Oriented Analysis for Microservice Architecture: an Exploratory Case Study
    (Institute of Electrical and Electronics Engineers, 2021) Ünlü, Hüseyin; Tenekeci, Samet; Yıldız, Ali; Demirörs, Onur
    The rapidly developing internet infrastructure together with the advances in software technology has enabled the development of cloud-based modern web applications that are much more responsive, flexible, and reliable compared to traditional monolithic applications. Such modern applications require new software design paradigms and architectures. Microservice-based architecture (MSbA), which aims to create small, isolated, loosely-coupled applications that work in cohesion, becoming widespread as one of these approaches. MSbA allows the developed applications to be deployed and maintained separately, as well as scaled on demand. However, there is no de facto method for the analysis and design of systems for these architectures. In this paper, we compared the usefulness of the object-oriented (OO) and event-oriented (EO) approaches for analyzing and designing MS-based systems. More specifically, we performed an exploratory case study to analyze, design, and implement a software application dealing with the 'application and evaluation process of graduate students at IzTech'. This paper discusses the results of this case study. We observe that the EO approaches have significant advantages with respect to the OO approaches.
  • Article
    Systematic Reviews in Model-Driven Engineering: a Tertiary Study
    (Hezârfen Havacılık ve Uzay Teknolojileri Enstitüsü, 2020) Akdur, Deniz; Demirörs, Onur
    To cope with growing complexity of software-intensive systems, model-driven engineering (MDE) has become a widely used approach in the industry by providing many (potential) benefits with different purposes. Although there has been an increasing interest in conducting secondary studies among MDE researchers such as surveys, systematic mapping (SM) and systematic literature review (SLR), there have been no tertiary study to synthesize the findings from all these existing secondary studies, which also examines various characteristics of software modeling (e.g., purposes, benefits and challenges) as a meta-analysis. The objective of this paper is to investigate and understand the state-of-the-practices in MDE based on the modeling characteristics by presenting a tertiary study (i.e., a systematic review of systematic reviews). To this end, we collected the set of all the existing 64 secondary studies in this field using a well-defined search strategy. This article presents inputs for different modeling stakeholders to better understand and use different purposes, benefits, and challenges of MDE by aggregating consolidated findings on this approach.
  • Conference Object
    Citation - WoS: 6
    Citation - Scopus: 6
    Mikroservis Mimarisinde Analiz ve Tasarım: Türkiye’den Bir İnceleme
    (IEEE, 2020) Bilgin, Burak; Ünlü, Hüseyin; Demirörs, Onur
    The demand for more flexible, responsive and reliable software applications and the availability of internet infrastructure to respond to this demand, led to a new generation of cloud-based web applications. As a result, cloud- based distributed web applications working together in a microservice-based architecture has gained popularity. The concept of microservice-based architecture is quite new and software organizations need to transform their culture to develop applications in this fashion. However, there is a lack of research studies in the literature that explores the common practices for the analysis and design of microservices. Thus, we performed a survey to explore the organizational choices on software analysis and design when working with microservices. In this paper, we present the results from Turkey. The results provide a snapshot of the software industry that utilizes microservices and suggests a set of challenges researchers can focus on in the area. © 2020 IEEE.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 3
    Automated Estimation of Functional Size From Code
    (IEEE, 2020) Özen, Özgesu; Özsoy, Bora; Aktılav, Busenur; Güleç, Eren Can; Demirörs, Onur
    Determination of the size of a software project is challenging as well as crucial for both self-employed software developers and corporate businesses. That's why it is subjected to a lot of academic studies where it is discussed how to determine the size more accurately. Functional Size Measurement (FSM) is one the most popular measurement techniques for a software from the point of the delivered functionality. However, the aspects of know-how, the cost, time, and manual operation creates difficulties to apply FSM techniques. This study aims to solve these issues by automating the measurement process to approximate the functional size of a project using the COSMIC Functional Size Measurement. The end product of this study is called 'Cosmic APP' that utilizes the sequence diagram of a software after reverse engineering it from the given code using a third-party tool called 'SequenceDiagram'. The working principles, the estimation process, and the obtained results of 'Cosmic APP' are described thoroughly in this paper. © 2020 IEEE.
  • Conference Object
    Citation - WoS: 3
    Citation - Scopus: 11
    Towards Modeling Patterns for Embedded Software Industry: Feedback From the Field
    (IEEE, 2018) Akdur, Deniz; Demirörs, Onur; Say, Bilge
    The analysis, design, implementation and testing of software for embedded systems are not trivial. Software modeling is a commonly used approach in the embedded software industry to manage complexity of these phases. The modeling approaches vary since the characteristics of modeling such as its purpose, the medium type used, the lifecycle phase used, differ among systems and industrial sectors. Our previous research identified and defined the modeling approach patterns in embedded software development projects based on quantitative data. In this paper, to validate and improve the pre-investigated pattern set, we present a series of semi-structured interviews over eight months with 53 embedded software professionals across a variety of target industrial sectors and roles. With the help of these interviews, the different modeling approach patterns in embedded software development were better understood and the hidden patterns not evident in the previous study were identified along with a documentation of personalized modeling experiences.
  • Conference Object
    Citation - Scopus: 3
    Exploring Reuse Levels in Erp Projects in Search of an Effort Estimation Approach
    (Institute of Electrical and Electronics Engineers, 2018) Demirörs, Onur; Küçükateş Ömüral, Neslihan
    Enterprise Resource Planning (ERP) projects have special characteristics that differentiate them from other kinds of software projects. Main difference that affects effort estimation results is high reuse rates of ERP projects. This paper presents our exploratory work to establish an approach to calculate reuse reflective size of ERP projects, which could be a primary input for effort estimation. We explored the usability of COSMIC function points as the base unit and its convertibility to reuse reflective size using reuse levels. We have performed a case study on an SAP Implementation project. We were able to calculate COSMIC size and reuse levels using the documents available for the project. We discuss the results as well as challenges and opportunities in the light of the case study.
  • Conference Object
    Utilizing Modeling Approach Patterns in the Embedded Software Industry
    (Institute of Electrical and Electronics Engineers Inc., 2019) Akdur, Deniz; Demirörs, Onur
    To cope with the growing complexity of software-intensive embedded system development, modeling is a widely used approach. The modeling approaches in the embedded software industry vary depending on many modeling characteristics (e.g., purpose, modeling rigor, medium type used, modeling stakeholder profile, etc.). In the light of our previous studies, we have identified modeling approach patterns of embedded software development projects and constructed a characterization model. This model not only identifies and defines modeling approach patterns of the stakeholder in embedded software development projects, but also gives recommendations for commonsense modeling practices. In this article, one of the application results of this characterization model, which was performed in Defense & Aerospace sector is presented. The model was successfully applied to the case, in which a series of both structured and semi-structured interviews with 17 embedded software professionals were conducted. The results show that identification of individual patterns provide insight for improvement both for individuals as well as larger units of operations such as projects and organizations.
  • Conference Object
    Citation - WoS: 15
    Citation - Scopus: 20
    Measureability of Functional Size in Agile Software Projects: Multiple Case Studies With Cosmic Fsm
    (IEEE, 2019) Hacaloğlu, Tuna; Demirörs, Onur
    Functional size measurement (FSM) has been used in software engineering for decades as a main driver for estimation and significant input for other various project management activities throughout the project life span. To apply FSM accurately at the early stages of software development process, especially for estimation purposes, functional user requirements need to be available in detail as required by the adopted FSM method. However, in agile software development, requirement specifications, in general, are kept minimal. For this reason, the adjustment of the requirements to the necessary granularity level has been articulated as one of the barriers preventing the diffusion of FSM practices among agile teams. In this paper, we take a closer look at this problem in order to investigate the usability of FSM and to reveal FSM related challenges empirically through case studies on real agile projects from different software organizations. This study also provides a snapshot of agile organizations in terms of requirement specification and estimation related practices. © 2019 IEEE.