La fiabilité du logiciel, c’est-à-dire sa capacité à produire les fonctionnalités attendues, est essentielle au succès des projets de développement logiciel. Afin de garantir cette fiabilité, les développeurs ont pour objectif de réduire le nombre de bogues présents dans le code source du logiciel.Une des techniques ayant pour but d’aider les développeurs dans cette tâche est l’utilisation de métriques logicielles, et notamment de métriques liées au procédé de développement.L’objectif général de cette thèse est de contribuer à la validation de métriques de procédé en étudiant leur relation avec la fiabilité. Ces métriques, une fois validées, pourront être utilisées dans des modèles de prédiction de bogues ayant pour but de mieux orienter les efforts de maintenance des développeurs ou pourront permettre de mettre en place des lignes de conduite relatives au procédé de développement. Devant l’étendue de ce domaine, nous avons centré nos contributions sur un aspect du procédé de développement qui est l’organisation des développeurs et avons observé cette organisation dans des projets open-source.En parallèle de la validation de ces métriques, nous avons contribué à l’amélioration de la méthodologie permettant l’extraction et l’analyse de métriques, grâce aux informations contenues dans les dépôts logiciels. / Reliability of a software, i.e. its capacity to produce the expected behaviour, is essential to the success of software projects. To ensure such reliability, developers need to reduce the amount of bugs in the source code of the software. One of the techniques available to help developers in this task is the use of software metrics, and especially metrics related to the development process.The general objective of this thesis is to contribute to the validation of process metrics, by studying their relationship with software reliability. These metrics, once validated, can be used in bug predictionmodels with the goal to guide maintenance efforts or can be used to create development guidelines. Given the extent of this domain, we chose to focus on one particular aspect of the development process, which is developers organisation, and we studied this organisation in open-source software projects.In parallel to the validation of process metrics, we contributed to the improvement of the methodology used to extract and analyse metrics, thanks to information available in software repositories.

Software fault prediction (SFP) has an important role in the process of improving software product quality by identifying fault-prone modules. Constructing quality models includes a usage of metrics that describe real world entities defined by numbers or attributes. Examining the nature of machine learning (ML), researchers proposed its algorithms as suitable for fault prediction. Moreover, information that software metrics contain will be used as statistical data necessary to build models for a certain ML algorithm. One of the most used ML algorithms is a Bayesian network (BN), which is represented as a graph, with a set of variables and relations between them. This thesis will be focused on the usage of process and static code metrics with BN learners for SFP. First, we provided an informal review on non-static code metrics. Furthermore, we created models that contained different combinations of process and static code metrics, and then we used them to conduct an experiment. The results of the experiment were statistically analyzed using a non-parametric test, the Kruskal-Wallis test. The informal review reported that non-static code metrics are beneficial for the prediction process and its usage is highly recommended for industrial projects. Finally, experimental results did not provide a conclusion which process metric gives a statistically significant result; therefore, a further investigation is needed.

The aim of this thesis is to map how the most common process-oriented methodologies and standards govern the issue of process ownership, define the role of a process owner and a comparison of these with a current practice in the corporate environment. The first part describes the theoretical concepts related to process management, including a description of selected methodologies. The following part is a questionnaire and its description followed by the expected responses based on previous theories. The last, third, part of the thesis contains an analysis based on the data obtained from the questionnaire respondents compared with the stated hypotheses and its evaluation.

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.