Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-17T21:35:20Z No. of bitstreams: 1 DanielAlencarDaCosta_TESE.pdf: 9198560 bytes, checksum: 463f875eda2671bd33beca615f72eef3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-18T22:34:50Z (GMT) No. of bitstreams: 1 DanielAlencarDaCosta_TESE.pdf: 9198560 bytes, checksum: 463f875eda2671bd33beca615f72eef3 (MD5) / Made available in DSpace on 2017-04-18T22:34:50Z (GMT). No. of bitstreams: 1 DanielAlencarDaCosta_TESE.pdf: 9198560 bytes, checksum: 463f875eda2671bd33beca615f72eef3 (MD5) Previous issue date: 2017-02-08 / The timely delivery of addressed software issues (i.e., bug fixes, enhancements, and new features) is what drives software development. Previous research has investigated what impacts the time to triage and address (or fix) issues. Nevertheless, even though an issue is addressed, i.e., a solution is coded and tested, such an issue may still suffer delay before being delivered to end users. Such delays are frustrating, since end users care most about when an addressed issue is available in the software system (i.e, released). In this matter, there is a lack of empirical studies that investigate why addressed issues take longer to be delivered compared to other issues. In this thesis, we perform empirical studies to understand which factors are associated with the delayed delivery of addressed issues. In our studies, we find that 34% to 98% of the addressed issues of the ArgoUML, Eclipse and Firefox projects have their integration delayed by at least one release. Our explanatory models achieve ROC areas above 0.74 when explaining delivery delay.We also find that the workload of integrators and the moment at which an issue is addressed are the factors with the strongest association with delivery delay.We also investigate the impact of rapid release cycles on the delivery delay of addressed issues. Interestingly, we find that rapid release cycles of Firefox are not related to faster delivery of addressed issues. Indeed, although rapid release cycles address issues faster than traditional ones, such addressed issues take longer to be delivered.Moreover, we find that rapid releases deliver addressed issues more consistently than traditional ones. Finally, we survey 37 developers of the ArgoUML, Eclipse, and Firefox projects to understand why delivery delays occur. We find that the allure of delivering addressed issues more quickly to users is the most recurrent motivator of switching to a rapid release cycle.Moreover, the possibility of improving the flexibility and quality of addressed issues is another advantage that are perceived by our participants. Additionally, the perceived reasons for the delivery delay of addressed issues are related to decision making, team collaboration, and risk management activities. Moreover, delivery delay likely leads to user/developer frustration according to our participants. Our thesis is the first work to study such an important topic in modern software development. Our studies highlight the complexity of delivering issues in a timely fashion (for instance, simply switching to a rapid release cycle is not a silver bullet that would guarantee the quicker delivery of addressed issues).