The project is described trough the life cycle of project management and is conceived through two parts: theoretical and practical part. A detailed analysis of all five phases of the project life cycle was made in the theoretical part, while in the practical part the application of all phases on the example of a high value project replacement of secondary equipment and auxiliary power supply at HE Đale is presented. Project management finds its application in today's turbulent and competitive environment. For successful project implementation with the help of project management, it is necessary to clearly define the goals and purpose of the project, implement the project through its life cycle, respecting the nature of the project and respond in a timely manner to problems that arise along the way. The project of replacing secondary equipment and auxiliary power supply at HPP Đale is exactly the type of project that is suitable for the application of project management. The project did not follow the standard form of the project life cycle phases, but was guided by the internal rules and norms of the companies that participated in the project, which in some segments led to disorganization in the implementation of the project. The project is of high-risk and complex nature, given that it was necessary to organize the parallel operation of several activities in such a way that it does not interfere with equipment closely related to the plant on which other hydropower plants depend and in a way that will not endanger workers or the environment. As a project of such a character, great attention was paid to the preparation of project documentation and updating and archiving it. The project can be viewed from different angles and divided into different phases, depending on the subject of interest. The specificity of the project is that any change in secondary equipment, telecommunications and auxiliary power supply had to be done in parallel. Ultimately, the Secondary equipment and auxiliary power replacement project is a project of long-term financial and sectoral benefits that also contributes to increasing reliability, trust among its users, electricity generation and increasing operational readiness.