Artifact-based research provides a mechanism whereby researchers may study the creation of software yet avoid many of the difficulties of direct observation and experimentation. Open source software forges are of great value to the software researcher, because they expose many of the artifacts of software development. However, many challenges affect the quality of artifact-based studies, especially those studies examining software evolution. This thesis addresses one of these threats: the presence of very large commits, which we refer to as "Cliff Walls." Cliff walls are a threat to studies of software evolution because they do not appear to represent incremental development. In this thesis we demonstrate the existence of cliff walls in open source software projects and discuss the threats they present. We also seek to identify key causes of these monolithic commits, and begin to explore ways that researchers can mitigate the threats of cliff walls.

Version Control Systems are a staple of modern software development and its usage is rapidly growing in education. Students often use Version Control Systems such as Git and GitHub during their education, though newly examined students are often found to lack mastery of industry standard practices. Manually monitoring and giving feedback to students is time consuming and requires a large amount of labor. Therefore, this paper proposes and evaluates an automated feedback system which analyses student assignment repositories an publishes feedback based on a set of data points. After the study, we attempt to measure any impact of the feedback on student performance. The study is unable to underline a significant impact. Students are also asked to reflect over the feedback and the reception was positive, further promoting future studies on the subject. / Versionshantering används idag flytigt inom mjukvaruutveckling och dess popularitet växer stadigt inom högre utbildning. Studenter får ofta lära sig att använda versionshanteringssystem såsom Git och GitHub under deras utbildning, trots detta saknar nyexaminerade studenter ofta tillräcklig kunskap om relevanta industristandarder. Att manuellt övervaka studenter och tillförse dem med respons på deras inlämningar är tidskrävande och kräver mycket arbetskraft. Mot bakgrund av detta föreslår och utvärderar vi i denna studie ett automatiskt responssystem med syftet att analysera studenters inlämningar samt återkoppla med relevant respons på ett antal datapunkter. Efter studiens slut görs en mätning av skillnader i studenternas resultat men ingen konkret slutsats kan sammanställas. Studenterna tillfrågades också att reflektera över responsen de tog del av. Deras svar samt studiens resultat pekar mot att ytterligare studier inom ämnet är väl motiverade.

In today’s digital landscape, maintaining the integrity of source code is crucial for delivering reliable and trustworthy software solutions. However, the increasing prevalence of attacks targeting source code repositories and version control systems (VCSs) poses significant challenges to source code integrity. Unauthorized access to source code repositories can lead to various security risks, including the introduction of malicious code or unauthorized approvals for pull requests. Security measures implemented on the remote server hosting the repository are typically insufficient to detect these types of attacks, resulting in changes potentially remaining undetected and becoming part of the deployed artifact. To address those issues, this study proposes GitBark, a framework that employs cryptographic methods to verify the integrity of a source code repository. GitBark achieves this by enforcing rules and policies on the commits made to the repository. Specifically, the study demonstrates that by formulating rules that utilize digital signatures, GitBark can effectively identify unauthorized changes and approvals. Moreover, GitBark prioritizes maintaining the local repository in a consistent and trustworthy state, reducing reliance on the remote server. Even if changes violating established rules are introduced to the remote repository, GitBark prevents their integration into the local repository. Consequently, users of GitBark can have confidence that their local repository remains a consistent and trustworthy version of the source code, without needing to place full trust on a remote server. An evaluation of GitBark, along with the devised rules, demonstrates its effectiveness in mitigating the threats identified in this study. Additionally, in terms of performance, GitBark incurs a modest overhead, both in time and storage. / I dagens digital värld, så är det viktigare än någonsin att källkodens integritet upprätthålls. Detta är kritiskt för att kunna leverera tillförlitlig och kvalitativ mjukvara. Den ständigt ökade förekomsten av attacker som riktar sig mot källkodsrepon och versionshanteringssystem gör dock upprätthållandet av källkodens integritet svårt. Obehörig åtkomst till källkodsrepo ger upphov till flera säkerhetsrisker såsom inkluderandet av skadlig kod eller obehöriga godkännanden av nya ändringar. De säkerhetsåtgärder som finns implementerade på värdserven där källkodsrepot lagras kan generellt sätt inte detektera dessa typer av attacker, vilket resulterar i att dessa typer av ändringar oftast förblir oupptäckta. För att adressera dessa problem, så presenterar denna studie GitBark, ett verktyg som utnyttjar kryptografiska medel för att verifiera integriteten av ett källkodsrepo. GitBark gör detta genom att kräva regler för commits som görs till källkodsrepot och validera att de upprätthålls. Mer specifikt, så visar att studien att genom att formulera regler som uttnyttjar digitala signaturer så kan GitBark effektivt identifiera oauktoriserade ändringar och godkännanden. Dessutom, prioriterar GitBark att alltid bibehålla det lokala källkodsrepot i ett konsekvent och trovärdigt tillstånd, för att minska beroendet på en remoteserver. Även ifall ändringar som inte uppfyller reglerna introduceras på remote-källkodsrepot så ser GitBark till att dessa ändringar aldrig integreras i det lokala repot. Följaktligen så kan användare av GitBark känna sig säkra i att det lokala källkodsrepot alltid förblir i ett konsekvent och trovärdigt tillstånd i relation till dem etablerade reglerna, utan att behöva förlita sig på en remoteserver. En evaluering av GitBark, tillsammans med de skapade reglerna påvisar dess effektivitet i att adressera de identifierade hoten i denna studie. Dessutom, vad gäller prestanda så har GitBark en liten påverkan både i tid och utrymme.

Having the skill to work with Version Control Systems (VCS) is an important aspect of most software development projects in the industry. But students may lack the knowledge on how to use it. By applying requirements on first year students of the Computer Science programme at KTH, this thesis aims to examine if that is enough to improve their VCS behaviour. This can be examined by applying requirements and then examining the metadata from GitHub. The results from this thesis show that the students committed a bit more when requirements were applied, but that the best way to get the students to commit more is to give them the knowledge on how to have a good commit behaviour. This is in line with previous research in the same area. / Versionshanteringssystem är ett viktigt verktyg i de flesta mjukvaruprojekt. Därför är det också en nödvändig kunskap att kunna arbeta med dem. Trots det så kan många datateknikstudenter sakna dessa kunskaper i hur man använder versionshantering optimalt. Därför ämnar detta arbete att undersöka om det är möjligt att förbättra förstaårsstudenterna på civilingenjörsprogrammet med inriktning datateknik på KTHs commitvanor genom att ställa krav på dem om ett minst antal commits per vecka. Krav kan ställas och sen är det möjligt att använda metadatan från GitHub för att besvara frågeställningen. Resultaten från detta arbete visar att även om studenterna committade lite mer med bara kraven, så var det framförallt efter att de fått kunskaper om bra commitbeteenden som de också förbättrade sitt eget beteende. Detta stämmer väl överens med tidigare forskning på området.

A gerência de configuração vem sendo estudada desde os anos sessenta. Inicialmente, era aplicada da mesma forma para software e hardware, sendo que no final dos anos setenta já havia padrões de gerência de configuração específicos para software. Com a crescente demanda por qualidade de software, as práticas de gerência de configuração vem sendo cada vez mais utilizadas no desenvolvimento de software, uma vez que a gerência de configuração de software é um dos processos fundamentais para se ter qualidade no desenvolvimento e manutenção de software. Embora cada vez mais amplamente utilizado, não existe um consenso de práticas e nomenclaturas sobre as práticas de gerência de configuração. Dessa forma, o objetivo deste trabalho é elaborar um modelo de avaliação do processo de Gerência de Configuração, que permite avaliar as práticas e processos fundamentais para a implantação da gerência de configuração, levando em consideração as práticas e processos descritos nas principais normas internacionais de desenvolvimento de software. Esse modelo de avaliação também permite que as ferramentas disponíveis para gerência de configuração sejam avaliadas, identificando quais práticas e processos elas auxiliam na execução. / The Configuration Management has been studied since the 70’s. In the beginning it was applied in the same way for software and hardware, but in the late 70’s there were some specific configuration management patterns defined for software. The demand for software quality has increased recently, this way the configuration management practices have been more used in software development, because the software configuration management is one of the most important processes to assess quality during software development or maintenance. Although its use is increasing, there is no consensus about the configuration management practices and the names applied to them. The objective of this work is to elaborate an evaluation model for configuration management process, to evaluate the practices and the fundamental processes to perform configuration management, based on the most important software development standards. This evaluation model can also be used to evaluate configuration management tools, identifying what practices and process it help to execute.

A gerência de configuração vem sendo estudada desde os anos sessenta. Inicialmente, era aplicada da mesma forma para software e hardware, sendo que no final dos anos setenta já havia padrões de gerência de configuração específicos para software. Com a crescente demanda por qualidade de software, as práticas de gerência de configuração vem sendo cada vez mais utilizadas no desenvolvimento de software, uma vez que a gerência de configuração de software é um dos processos fundamentais para se ter qualidade no desenvolvimento e manutenção de software. Embora cada vez mais amplamente utilizado, não existe um consenso de práticas e nomenclaturas sobre as práticas de gerência de configuração. Dessa forma, o objetivo deste trabalho é elaborar um modelo de avaliação do processo de Gerência de Configuração, que permite avaliar as práticas e processos fundamentais para a implantação da gerência de configuração, levando em consideração as práticas e processos descritos nas principais normas internacionais de desenvolvimento de software. Esse modelo de avaliação também permite que as ferramentas disponíveis para gerência de configuração sejam avaliadas, identificando quais práticas e processos elas auxiliam na execução. / The Configuration Management has been studied since the 70’s. In the beginning it was applied in the same way for software and hardware, but in the late 70’s there were some specific configuration management patterns defined for software. The demand for software quality has increased recently, this way the configuration management practices have been more used in software development, because the software configuration management is one of the most important processes to assess quality during software development or maintenance. Although its use is increasing, there is no consensus about the configuration management practices and the names applied to them. The objective of this work is to elaborate an evaluation model for configuration management process, to evaluate the practices and the fundamental processes to perform configuration management, based on the most important software development standards. This evaluation model can also be used to evaluate configuration management tools, identifying what practices and process it help to execute.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-11-06T19:48:59Z No. of bitstreams: 2 Dissertação - Marcello Henrique Dias de Moura - 2013.pdf: 3325482 bytes, checksum: 45be62e46fd5fda90d1d0561482a3d85 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2017-11-06T19:49:14Z (GMT) No. of bitstreams: 2 Dissertação - Marcello Henrique Dias de Moura - 2013.pdf: 3325482 bytes, checksum: 45be62e46fd5fda90d1d0561482a3d85 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-06T19:49:14Z (GMT). No. of bitstreams: 2 Dissertação - Marcello Henrique Dias de Moura - 2013.pdf: 3325482 bytes, checksum: 45be62e46fd5fda90d1d0561482a3d85 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2013-03-22 / Version Control Systems are repositories that store source code changes done by software developers. Research that extracts data from these repositories for analysis can be classified into two groups: those that focus on the development process and the ones that focus on the developers. The present dissertation investigates the second case and contributes to the field by providing: (a) the definition of a history file that summarizes changes made to software in line and file levels, (b) a set of metrics to evaluate the work of the developers; and (c) two approaches for comparing the developers based on their metrics. A computational system that implements these metrics and approaches was built and applied to two case studies of real software development projects. The results obtained in the studies were positive. They were consistent with the general perception of project managers about the work done by the developers. They also leaded to new ideas for improving the research.We believe that these contributions are a step towards a better understanding and characterization of the way about how software developers work. / Repositórios de Controle de Versão são sistemas que armazenam mudanças no código fonte realizadas por desenvolvedores de software. As pesquisas que extraem dados desses repositórios para análise podem ser classificadas em dois grupos: as que focam no processo de desenvolvimento e as que focam no desenvolvedor. O presente trabalho investiga o segundo aspecto contribuindo para o assunto com: (a) a definição de um histórico de arquivos que sumariza as mudanças realizadas no software em nível de linha e de arquivo; (b) um conjunto de métricas visando avaliar o trabalho dos desenvolvedores; e (c) duas propostas de abordagem para comparar os desenvolvedores. Um sistema computacional que implementa essas métricas e as abordagens foi construído, tendo sido aplicado em dois estudos de casos envolvendo projetos reais de desenvolvimento de software. Os resultados obtidos nos estudos foram positivos, coincidindo, em geral, com a percepção de gerentes de projetos sobre o trabalho dos desenvolvedores e apontando para novas ideias de evolução da pesquisa. Consideramos que este é um passo no sentido de entender e caracterizar melhor a forma de trabalho dos desenvolvedores.

This master's thesis is about code ownership in software projects and creating a tool that would improve cooperation by identifying code owners. The theoretical foundation for code ownership starts from Extreme Programming, explaining models of code ownership and the impact of code ownership on cooperation among teams and team members. The concept is demonstrated on a concrete software firm, where a potential for improvement is identified. The potential is exploited by a software tool, which is designed in the this thesis. The tool is capable of identifying code owners and experts for specific areas in the code based on data gathered from a version control system. The resulting information is made easily accessible. The tool is used to conduct a code ownership research in several projects, which allows me to confirm accuracy of the results. Usability and benefits of the tool is discussed in the final chapter.

The maturing capabilities of Artificial Intelligence (AI) and Machine Learning (ML) have resulted in increased attention in research and development on adopting AI and ML in 5G and future networks. With the increased maturity, the usage of AI/ML models in production is becoming more widespread, and maintaining these systems is more complex and likely to incur technical debt when compared to standard software. This is due to inheriting all the complexities of traditional software in addition to ML-specific ones. To handle these complexities the field of ML Operations (MLOps) has emerged. The goal of MLOps is to extend DevOps to AI/ML and therefore speed up development and ease maintenance of AI/ML-based software, by, for example, supporting automatic deployment, monitoring, and continuous re-training of models. This thesis investigates how to construct an MLOps workflow by selecting a number of tools and using these to implement a workflow. Additionally, different approaches for triggering re-training are implemented and evaluated, resulting in a comparison of the triggers with regards to execution time, memory and CPU consumption, and the average performance of the Machine learning model.

The main goal of this thesis is to describe the implementation of continuous integration into the k-Wave project. The thesis focuses primarily on the version written in the C/C++ language with the usage of the OpenMP library which typically runs on supercomputers. Accordingly, many of popular workflows and approaches ought to be adapted, a few more created. The outcome of the thesis is a complete solution with real and practical usage. The author provides design, tools selection, runtime environment administration and configuration for each one of the used services. Software implementation of the basic framework is used in order to utilize running tests on the supercomputers. Furthermore, the implementation of chosen types of regression and unit tests are performed. Realisation is based on Gitlab and Jenkis services that are running on separated Docker containers.