This study originally emanated from the debate on value creation through projects, which has become more prevalent in project management literature in recent times. Earned value analysis, which is widely used to measure and report the performance of project value, does not include the occurrence of value leaks in its calculations and reporting. Although there is a scarcity of literature on the issue of value leaks during project deployment, it is considered to be a big issue which can make or break a project’s value success. This lack of research is more pronounced in network expansion projects in the Ghanaian telecommunication industry, however, considering the level of investment by these network operators, and their contribution to economic growth, the occurrence of value leaks can be suspected. Therefore, the overall aim of the study was to develop a diagnostic model that aids in the easy identification of value leaks, so that they can be controlled, and remedied to minimise the forgone unrealised project value. In view of this, the study adopted an exploratory sequential mixed research design. The qualitative phase employed a multiple-case study approach to explore the concept of value leaks and the extent to which it becomes problematic in delivering overall project value. The quantitative phase, through a survey study, adopted factor analysis to test and validate the findings from the case study, and analyses were also performed to test the conceptual model fit to the retained dataset. The findings culminated in the development of the “Value Leaks-Flashlight”, with an add-on called the “Tolerable Nut” to theorise the concept of value leaks. This practical establishment of the value leak concept cemented the development of the value leaks diagnostic model through the application of the “CIIR” acronym, which fulfils the overall aim of the study. The study contributes to the contemporary literature in the field of project management, as the concept of project value leaks is still gaining prominence, and only a few empirical studies have thus far been conducted. The concept of value leaks enlightens the perspective of project management practitioners in their quest to achieve value through projects. / Business Management / D. Phil. (Management Studies)