Many organizations use project management maturity models to improve their project performance. These systematic and sequential frameworks are designed to help organizations quantify their project management maturity and improve their project management processes. However, these models rarely put enough emphasis on project reviews as tools to improve project performance, because, too often, project reviews are considered as non-productive administrative processes. The lack of emphasis on project reviews in project management maturity models is also illustrated by the limited amount of research published on the relationship between project reviews and project performance. Based on the concept of project management maturity models, this dissertation presents a project review maturity model used to measure the project review maturity for four (4) types of reviews (routine, gate, post-mortem, and focused-learning) as well as the overall project review maturity. In addition, this research establishes the quantitative relationship between project review maturity and project performance. This dissertation also quantifies the concept of project review performance and its relationship with project performance for all four (4) types of reviews, as well as for the overall project review performance. Finally, this research provides enablers, barriers, and best practices for effective reviews, based on the answers of written interview questions, and observations from a post-mortem review meeting at a highly-technical organization. The empirical case study and survey analysis conducted by this dissertation led to some unique findings. Five (5) specific conclusions were developed: ●Organizations use all types of reviews in their project management procedures, and view each review role differently. ●Some reviews are more related than others to project performance, although generally, review maturity and performance are significantly relevant to project performance. ●Organization culture (beliefs, expected actions, etc.) is not significantly relevant to project team members when assessing project status or PM procedures during project life-cycle. ●Post-mortem and focused-learning reviews are linked with higher levels of learning than routine and gate reviews. ●Effective reviews need managerial support. This research is the first of its kind to show significant positive relationships between project review maturity and performance with project performance and to provide quantifiable results for organizations to further improve their review processes.