Although bug tracking systems are fundamental to support virtually any software development process, they are currently suboptimal to support the needs and complexities of large communities. This dissertation first presents a study showing empirical evidence that the traditional interface used by current bug tracking systems invites much noise—unreliable, unuseful, and disorganized information—into the ecosystem. We find that noise comes from, not only low-quality contributions posted by inexperienced users or from conflicts that naturally arise in such ecosystems, but also from the difficulty of fitting the complex bug resolution process and knowledge into the linear sequence of comments that current bug tracking systems use to collect and organize information. Since productivity in bug tracking systems relies on bug reports with accessible and realible information, this leaves contributors struggling to work on and to make sense of the dumps of data submitted to bug reports and, thus, impacting productivity. Next generation bug tracking systems should be more than a tool for exchanging unstructured textual comments. They should be an ecosystem that is tailored for collaborative knowledge building, leveraging the power of the masses to collect reliable and useful information about bugs, providing mechanisms and incentives to verify the validity of such information and mechanisms to organize such information, thus, facilitating comprehension and reasoning. To bring bug tracking systems towards this vision, we present three orthogonal approaches aiming at increasing the usefulness and realiability of contributions and organizing information to improve understanding and reasoning. To improve the usefulness and realibility of contributions we propose the addition of game mechanisms to bug tracking systems, with the objective of motivating contributors to post higher-quality content. Through an empirical investigation of Stack Overflow we evaluate the effects of the mechanisms in such a collaborative software development ecosystem and map a promissing approach to use game mechanisms in bug tracking systems. To improve data organization, we propose two complementary approaches. The first is an automated approach to data organization, creating bug report summaries that make reading and working with bug reports easier, by highlighting the portions of bug reports that expert developers would focus on, if reading the bug report in a hurry. The second approach to improve data organization is a fundamental change on how data is collected and organized, eliminating comments as the main component of bug reports. Instead of comments, users contribute informational posts about bug diagnostics or solutions, allowing users to post contextual comments for each of the different diagnostic iiior solution posts. Our evaluations with real bug tracking system users find that they consider the bug report summaries to be very useful in facilitating common bug tracking system tasks, such as finding duplicate bug reports. In addition, users found that organzing content though diagnostic and solution posts to significanly facilitate reasoning about and searching for relevant information. Finally, we present future directions of work investigating how next generation bug tracking systems could combine the use of the three approaches, such that they benefit from and build upon the results of the other approaches. Next generation bug tracking systems should be more than a tool for exchanging unstructured textual comments. They should be an ecosystem that is tailored for collaborative knowledge building, leveraging the power of the masses to collect reliable and useful information about bugs, providing mechanisms and incentives to verify the validity of such information and mechanisms to organize such information, thus, facilitating comprehension and reasoning. To bring bug tracking systems towards this vision, we present three orthogonal approaches aiming at increasing the usefulness and realiability of contributions and organizing information to improve understanding and reasoning. To improve the usefulness and realibility of contributions we propose the addition of game mechanisms to bug tracking systems, with the objective of motivating contributors to post higher-quality content. Through an empirical investigation of Stack Overflow we evaluate the effects of the mechanisms in such a collaborative software development ecosystem and map a promissing approach to use game mechanisms in bug tracking systems. To improve data organization, we propose two complementary approaches. The first is an automated approach to data organization, creating bug report summaries that make reading and working with bug reports easier, by highlighting the portions of bug reports that expert developers would focus on, if reading the bug report in a hurry. The second approach to improve data organization is a fundamental change on how data is collected and organized, eliminating comments as the main component of bug reports. Instead of comments, users contribute informational posts about bug diagnostics or solutions, allowing users to post contextual comments for each of the different diagnostic iiior solution posts. Our evaluations with real bug tracking system users find that they consider the bug report summaries to be very useful in facilitating common bug tracking system tasks, such as finding duplicate bug reports. In addition, users found that organzing content though diagnostic and solution posts to significanly facilitate reasoning about and searching for relevant information. Finally, we present future directions of work investigating how next generation bug tracking systems could combine the use of the three approaches, such that they benefit from and build upon the results of the other approaches.

Although bug tracking systems are fundamental to support virtually any software development process, they are currently suboptimal to support the needs and complexities of large communities. This dissertation first presents a study showing empirical evidence that the traditional interface used by current bug tracking systems invites much noise—unreliable, unuseful, and disorganized information—into the ecosystem. We find that noise comes from, not only low-quality contributions posted by inexperienced users or from conflicts that naturally arise in such ecosystems, but also from the difficulty of fitting the complex bug resolution process and knowledge into the linear sequence of comments that current bug tracking systems use to collect and organize information. Since productivity in bug tracking systems relies on bug reports with accessible and realible information, this leaves contributors struggling to work on and to make sense of the dumps of data submitted to bug reports and, thus, impacting productivity. Next generation bug tracking systems should be more than a tool for exchanging unstructured textual comments. They should be an ecosystem that is tailored for collaborative knowledge building, leveraging the power of the masses to collect reliable and useful information about bugs, providing mechanisms and incentives to verify the validity of such information and mechanisms to organize such information, thus, facilitating comprehension and reasoning. To bring bug tracking systems towards this vision, we present three orthogonal approaches aiming at increasing the usefulness and realiability of contributions and organizing information to improve understanding and reasoning. To improve the usefulness and realibility of contributions we propose the addition of game mechanisms to bug tracking systems, with the objective of motivating contributors to post higher-quality content. Through an empirical investigation of Stack Overflow we evaluate the effects of the mechanisms in such a collaborative software development ecosystem and map a promissing approach to use game mechanisms in bug tracking systems. To improve data organization, we propose two complementary approaches. The first is an automated approach to data organization, creating bug report summaries that make reading and working with bug reports easier, by highlighting the portions of bug reports that expert developers would focus on, if reading the bug report in a hurry. The second approach to improve data organization is a fundamental change on how data is collected and organized, eliminating comments as the main component of bug reports. Instead of comments, users contribute informational posts about bug diagnostics or solutions, allowing users to post contextual comments for each of the different diagnostic iiior solution posts. Our evaluations with real bug tracking system users find that they consider the bug report summaries to be very useful in facilitating common bug tracking system tasks, such as finding duplicate bug reports. In addition, users found that organzing content though diagnostic and solution posts to significanly facilitate reasoning about and searching for relevant information. Finally, we present future directions of work investigating how next generation bug tracking systems could combine the use of the three approaches, such that they benefit from and build upon the results of the other approaches. Next generation bug tracking systems should be more than a tool for exchanging unstructured textual comments. They should be an ecosystem that is tailored for collaborative knowledge building, leveraging the power of the masses to collect reliable and useful information about bugs, providing mechanisms and incentives to verify the validity of such information and mechanisms to organize such information, thus, facilitating comprehension and reasoning. To bring bug tracking systems towards this vision, we present three orthogonal approaches aiming at increasing the usefulness and realiability of contributions and organizing information to improve understanding and reasoning. To improve the usefulness and realibility of contributions we propose the addition of game mechanisms to bug tracking systems, with the objective of motivating contributors to post higher-quality content. Through an empirical investigation of Stack Overflow we evaluate the effects of the mechanisms in such a collaborative software development ecosystem and map a promissing approach to use game mechanisms in bug tracking systems. To improve data organization, we propose two complementary approaches. The first is an automated approach to data organization, creating bug report summaries that make reading and working with bug reports easier, by highlighting the portions of bug reports that expert developers would focus on, if reading the bug report in a hurry. The second approach to improve data organization is a fundamental change on how data is collected and organized, eliminating comments as the main component of bug reports. Instead of comments, users contribute informational posts about bug diagnostics or solutions, allowing users to post contextual comments for each of the different diagnostic iiior solution posts. Our evaluations with real bug tracking system users find that they consider the bug report summaries to be very useful in facilitating common bug tracking system tasks, such as finding duplicate bug reports. In addition, users found that organzing content though diagnostic and solution posts to significanly facilitate reasoning about and searching for relevant information. Finally, we present future directions of work investigating how next generation bug tracking systems could combine the use of the three approaches, such that they benefit from and build upon the results of the other approaches.

I denna rapport utreds en ostrukturerad och splittrad IT miljö på Electrolux. Miljön saknade flöden och processer för bland annat felhantering. Omodern hård- och mjukvara samt bristande kommunikation mellan produktorganisationen och Electrolux IT medförde förhöjd risk för nätverksattacker och virusangrepp. Situationen medförde onödiga kostnader, eftersatt säkerhet samt otillräcklig IT-stöd för slutanvändarna. Målet med detta arbete är att uppnå en enad, strukturerad och väletablerad IT-miljö med klara rutiner och flöden för felhantering av hård- och mjukvaror. Enhetliga hård- och mjukvaror samt standardiserade IT-lösningar är av stor vikt. Hinder för en migration till en väletablerad IT-miljö skulle med detta arbete också elimineras. En nulägesanalys utfördes tillsammans med en inventering av hård- och mjukvara. Detta för att få en överblick och för att förstå hur verksamheten fungerade, samt finna eventuella IT brister. Resultatet visade på behovet av en migration av en grupp datorer till en etablerad IT miljö med fungerande rutiner och processer. Implementationsplan samt manual för migration genererades i rapporten. En utvärdering av olika verktyg för begränsade administrativa rättigheter i slutanvändarnas datorer utfördes. Det bäst lämpade verktyget för Electrolux var Avecto Privilege Guard som testades och konfigurerades. Detta för att tillgodogöra produktorganisationens behov. Lösningsförslag för att möta kraven och standarden från både Electrolux-IT samt produktorganisationen framtogs och presenteras i resultatet. Resultatet av detta examensarbete påvisade ett stort behov av en IT-koordinator för en bättre kommunikation och ett bättre samarbete mellan organisationerna. En rekommendation om detta presenteras i slutsatsen tillsammans med förslag på andra förbättringar och åtgärder. / This report investigated an unstructured and fragmented IT environment at Electrolux. The environment lacked flows and processes for troubleshooting. Outdated hardware and software and a lack of communication between the product organization and the IT organization, resulted in an increased risk of network attacks and virus attacks. The situation resulted in unnecessary costs, neglected security and inadequate IT support for the end-users. The goal of this work is to achieve a unified, structured and well-established IT environment with clear procedures and flows for the troubleshooting of computer hardware and software. Uniform hardware and software as well as standardized IT solutions is of great importance. Barriers to migration to a well-established IT environment would with this work also be eliminated. A situation analysis was conducted together with an inventory of hardware and software. This was done to get an overview and to understand how the business worked, also to find possible IT failures. The results showed the need for a migration of a group of computers to an established IT environment with operational procedures and processes. An implementation plan and manual for the migration was generated in the report. An evaluation of the different tools for limited administrative rights on end-user computers was also performed. The most suitable tool for Electrolux was Avecto Privilege Guard which was tested and configured. This was done to assimilate the product organization’s needs. Solution´s to meet the requirements from both Electrolux IT and product organization was developed and is presented in the results. The results of this thesis showed a great need of an IT coordinator for a better communication and better cooperation between the organizations. A recommendation regarding this was presented to Electrolux together with suggestions for improvements and measures.

Today’s world is a network of interconnected systems that are always running to facilitate information exchange so people can carry out their daily activities. Software applications are constantly evolving to meet the increasing expectations of the growing market, thereby giving rise to the development of large complex systems. It is very likely for these complex systems to encounter bugs which is a situation that can cause errors in software. These bugs can prevent the systems from operating as intended, slowing down software development and deployment, and causing delays in deadlines. This study undertook a systematic literature review to find trends in the field of bug prioritization. Software bug prioritization can help developers determine the order of fixing bugs by assigning priority levels based on the severity analysis. This study aims to identify the most promising techniques that can change the bug prediction and resolution process. It is observed that machine learning techniques (ML) have been gaining popularity in addressing the bug prioritization issue since they can automatically assign priority levels. However, these ML techniques also have limitations addressed in this study along with a taxonomic classification of identified techniques. The review obtained 34 manuscripts based on study selection criteria. These manuscripts discovered 63 unique bug prioritization techniques, including a mix of ML, data reduction and hybrid techniques. It is evident that though these techniques perform automatic prioritization, they can sometimes be slow and lack consistency in the accuracy of results.

In recent years, software tools used for Global Software Development (GSD) processes (e.g., continuous integration, version control and bug tracking) are increasingly being deployed in the cloud to serve multiple users. Multitenancy is an important architectural property in cloud computing in which a single instance of an application is used to serve multiple users. There are two key challenges of implementing multitenancy: (i) ensuring isolation either between multiple tenants accessing the service or components designed (or integrated) with the service; and (ii) resolving trade-offs between varying degrees of isolation between tenants or components. The aim of this thesis is to investigate how to architect the deployment of cloud-hosted service while guaranteeing the required degree of multitenancy isolation. Existing approaches for architecting the deployment of cloud-hosted services to serve multiple users have paid little attention to evaluating the effect of the varying degrees of multitenancy isolation on the required performance, resource consumption and access privilege of tenants (or components). Approaches for isolating tenants (or components) are usually implemented at lower layers of the cloud stack and often apply to the entire system and not to individual tenants (or components). This thesis adopts a multimethod research strategy to providing a set of novel approaches for addressing these problems. Firstly, a taxonomy of deployment patterns and a general process, CLIP (CLoud-based Identification process for deployment Patterns) was developed for guiding architects in selecting applicable cloud deployment patterns (together with the supporting technologies) using the taxonomy for deploying services to the cloud. Secondly, an approach named COMITRE (COmponent-based approach to Multitenancy Isolation Through request RE-routing) was developed together with supporting algorithms and then applied to three case studies to empirically evaluate the varying degrees of isolation between tenants enabled by multitenancy patterns for three different cloud-hosted GSD processes, namely-continuous integration, version control, and bug tracking. After that, a synthesis of findings from the three case studies was carried out to provide an explanatory framework and new insights about varying degrees of multitenancy isolation. Thirdly, a model-based decision support system together with four variants of a metaheuristic solution was developed for solving the model to provide an optimal solution for deploying components of a cloud-hosted application with guarantees for multitenancy isolation. By creating and applying the taxonomy, it was learnt that most deployment patterns are related and can be implemented by combining with others, for example, in hybrid deployment scenarios to integrate data residing in multiple clouds. It has been argued that the shared component is better for reducing resource consumption while the dedicated component is better in avoiding performance interference. However, as the experimental results show, there are certain GSD processes where that might not necessarily be so, for example, in version control, where additional copies of the files are created in the repository, thus consuming more disk space. Over time, performance begins to degrade as more time is spent searching across many files on the disk. Extensive performance evaluation of the model-based decision support system showed that the optimal solutions obtained had low variability and percent deviation, and were produced with low computational effort when compared to a given target solution.

Nowadays the development speed of new software products is a key to success and it is not important whether the aim is to make customer's urges satisfied or get ahead of one's competitors and fill the market gap. Because of the increase of development speed the demands on the saving process of software quality are increasing. There are two types of tools that are supporting the process of software quality assurance. Firstly, we talk about comprehensive testing tools of commercial character that usually include many functions, but their purchase is extremely expensive. On the other hand there are open-source tools that are available for free, they function on many kinds of operating systems and it is possible to modify them. Unfortunately their functions are basically focused on a certain subset of controlling the software quality assurance. Company TRASK solution a.s. has decided to change this current situation, so it asked competence centre Software Quality Assurance at the University of Economics in Prague in order to create Integrated Testing Node (ITN) that would combine the advantages of open-source tools. Moreover, it would offer broad range of functions as commercial solution. The purpose of this thesis is to describe relevant phases of the process of creating the Integrated Testing Node from the factual and methodical point of view. This aim is divided into partial aims included task analysis and the proposal of solving system, open-source products portfolio analysis, choice of the most convenient tools for following integration, choosing the method of information system building, evaluating the feedback from a client and the proposal of future development of this tool. As far as the biggest contribution of this thesis is concerned, it is the realisation of ITN project that can be used during information classes at the University of Economics in Prague. Furthermore, it can be used as the control of software quality in commercial companies.

The title of graduation work is development of techniques of software testing. The objective of research is studying of the testing process, defect types in the software and their tracking, methods of creating and applying test cases, and development of auto-test project for the web service “Expert”. An additional objective is to conduct stress testing for the web service "Expert". The first part is devoted to the theoretical foundations of testing: a place of testing in software development, testing process in it-companies, review of defects and their tracking, and techniques of creating tests and their applying. The second part is devoted to the review of software for load testing and it’s practical usage for testing the web service “Expert”. The last part is devoted to the study of automation functional testing and development of the auto test project for the web service “Expert”. The graduation work consists of an introduction, 12 chapters and conclusion on 106 pages, including 55 figures and the list of 15 references. / Тема выпускной квалификационное работы: разработка методики тестирования программного обеспечения. Цель работы: изучение процесса тестирования, видов дефектов в ПО и их отслеживание, способов создания и применения тест кейсов, и, на основе полученных знаний, разработка проекта авто-тестов для веб-сервиса "Эксперт". Дополнительной целью является проведение нагрузочного тестирования для веб-сервиса "Эксперт". Первая часть работы посвящена теоретическим основам тестирования: место тестирования в разработке ПО, процесс тестирования в IT-компаниях, обзор дефектов, способов их отслеживания, а также техник создания тестов и их применение. Вторая часть посвящена обзору ПО для нагрузочного тестирования и его практическое использование для тестирования веб-сервиса «Эксперт». Третья часть посвящена изучению процесса автоматизации функционального тестирования и разработке авто-тестов для веб-сервиса «Эксперт». Выпускная работа состоит из введения, 12 глав и заключения, изложенных на 106 страницах, а также списка литературы и приложений. В работе имеется 55 рисунков. Список литературы содержит 15 наименований.

Large open-source software projects involve developers with a wide variety of backgrounds and expertise. Such software projects furthermore include many internal APIs that developers must understand and use properly. According to the intended purpose of these APIs, they are more or less frequently used, and used by developers with more or less expertise. In this paper, we study the impact of usage patterns and developer expertise on the rate of defects occurring in the use of internal APIs. For this preliminary study, we focus on memory management APIs in the Linux kernel, as the use of these has been shown to be highly error prone in previous work. We study defect rates and developer expertise, to consider e.g., whether widely used APIs are more defect prone because they are used by less experienced developers, or whether defects in widely used APIs are more likely to be fixed.