Computer Engineering / Bilgisayar Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/10
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Conference Object Citation - WoS: 2Citation - Scopus: 2Effort Prediction With Limited Data: a Case Study for Data Warehouse Projects(IEEE, 2022) Unlu, Huseyin; Yildiz, Ali; Demirors, OnurOrganizations may create a sustainable competitive advantage against competitors by using data warehouse systems with which they can assess the current status of their operations at any moment. They can analyze trends and connections using up-to-date data. However, data warehouse projects tend to fail more often than other projects as it can be tough to estimate the effort required to build a data warehouse system. Functional size measurement is one of the methods used as an input for estimating the amount of work in a software project. In this study, we formed a measurement basis for DWH projects in an organization based on the COSMIC Functional Size Measurement Method. We mapped COSMIC rules on two different architectures used for DWH projects in the organization and measured the size of the projects. We calculated the productivity of the projects and compared them with the organization's previous projects and DWH projects in the ISBSG repository. We could not create an organization-wide effort estimation model as we had a limited number of projects. As an alternative, we evaluated the success of effort estimation using DWH projects in the ISBSG repository. We also reported the challenges we faced during the size measurement process.Conference Object Citation - WoS: 7Citation - Scopus: 12Utilization of Three Software Size Measures for Effort Estimation in Agile World: a Case Study(IEEE, 2022) Unlu, Huseyin; Hacaloglu, Tuna; Buber, Fatma; Berrak, Kivilcim; Leblebici, Onur; Demirors, OnurFunctional size measurement (FSM) methods, by being systematic and repeatable, are beneficial in the early phases of the software life cycle for core project management activities such as effort, cost, and schedule estimation. However, in agile projects, requirements are kept minimal in the early phases and are detailed over time as the project progresses. This situation makes it challenging to identify measurement components of FSM methods from requirements in the early phases, hence complicates applying FSM in agile projects. In addition, the existing FSM methods are not fully compatible with today's architectural styles, which are evolving into event-driven decentralized structures. In this study, we present the results of a case study to compare the effectiveness of different size measures: functional -COSMIC Function Points (CFP)-, event-based - Event Points-, and code length-based - Line of Code (LOC)- on projects that were developed with agile methods and utilized a microservice- based architecture. For this purpose, we measured the size of the project and created effort estimation models based on three methods. It is found that the event-based method estimated effort with better accuracy than the CFP and LOC-based methods.Conference Object Citation - WoS: 4Citation - Scopus: 12Event 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, OnurThe 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, OnurTo 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: 6Citation - Scopus: 6Mikroservis Mimarisinde Analiz ve Tasarım: Türkiye’den Bir İnceleme(IEEE, 2020) Bilgin, Burak; Ünlü, Hüseyin; Demirörs, OnurThe 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: 3Citation - Scopus: 11Towards Modeling Patterns for Embedded Software Industry: Feedback From the Field(IEEE, 2018) Akdur, Deniz; Demirörs, Onur; Say, BilgeThe 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: 3Exploring Reuse Levels in Erp Projects in Search of an Effort Estimation Approach(Institute of Electrical and Electronics Engineers, 2018) Demirörs, Onur; Küçükateş Ömüral, NeslihanEnterprise 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, OnurTo 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: 15Citation - Scopus: 20Measureability of Functional Size in Agile Software Projects: Multiple Case Studies With Cosmic Fsm(IEEE, 2019) Hacaloğlu, Tuna; Demirörs, OnurFunctional 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.Conference Object Citation - WoS: 3Citation - Scopus: 4Evaluating Software Security Change Requests: a Cosmic-Based Quantification Approach(Institute of Electrical and Electronics Engineers, 2019) Haoues, Mariem; Sellami, Asma; Ben-Abdallah, Hanene; Demirörs, OnurSoftware project scope defines functional and non-functional requirements. These requirements may change to satisfy the customers' needs. However, the control of scope creep represents one of the success keys in software project management. Changes in non-functional requirements affect the ISO/IEC 25010 quality characteristics such as security, portability, etc. Furthermore, some of these quality characteristics may evolve throughout the software life cycle into functional requirements. In this paper, we explore the use of COSMIC method-ISO/IEC 19761 to quantify and evaluate security change requests. Measuring the functional size of security change requests allows stakeholders to make appropriate decisions about whether to accept, defer, or deny the change. © 2019 IEEE.