Thesis for scientific degree of Doctor of Technical Sciences in specialty: 05.13.22 – Project and Program Management. Odessa National Polytechnic University, Odessa, 2020. The dissertation research solves the scientific problem of formation of new models and design of new methods of proactive project management in the development of software product lifecycle, which provide the laying of methodological bases of proactive project management for software systems reengineering, which makes it possible to work with multilevel software systems using complex project assessment tools. Systematization of leading project management methodologies has been further developed, it has been expanded by forming the concept of a proactive project management for the development of the life cycle of software systems and products, which makes it possible to determine the feasibility of a targeted reengineering program at the project assessment stage. Reengineering projects are managed through a set of tools, including through the utilization of reuse components and CASE-systems. According to forecasts, the utilization of reuse components can reduce the cost of the software system 4 times compared to a new development. Methods of the proactive project management of the software systems through design development have been formalized, they differ in the system transformation paradigm formation, making it possible to integrate software products into updated design complexes. Models of the proactive management of projects linguistic and information support development have been formed with the help of dynamic environment of generative grammars, making it possible to get rid of dead-end chains when translating from one programming language to another. Models for proactive management of the development of behavioral and structural parts of software systems reengineering projects have been improved, which are characterized by introduction of updated structures of unified diagram models, making it possible to maintain positive properties of relations between design classes, components and entities of software systems, regardless of the programming language. The method of calculating project indicators by Karner project points has been improved, which is characterized by the introduction of additions and extensions to the processes of software system reengineering, which makes it possible to reduce the estimation error of the projected cost of the project implementation by 17 – 19%, compared with the Karner method. Idealized models for managing the process of reengineering project evaluation have been developed, which differ in the introduction of resource and time constraints on the project implementation, which makes it possible to increase accuracy estimation of the project cost for the software systems re-design. The proposed idealized project management models for software systems re-engineering represent evolutionary spirals constructed in the cylindrical coordinate system. The method for presenting the software systems reengineering project assessment has been developed, characterized by the use of the design coefficients tool, making it possible to manage the qualitative changes in the of the re-design graphical models configuration in the form of corresponding hodographs of the software systems reengineering projects. The maximum value of the relative error of software systems reengineering project assessment does not exceed 16% by the method of design coefficients according to the data of 12 completed projects. The average value of the relative error is 8%. Practically oriented results of complex experimental researches on proactive project management for software systems development have been generalized and recommendations for elaborating software products system architecture, intended for development, have been formed. The software-methodological complex of projects re-engineering planning management has been developed for use by the project management team as part of the project management office. The proposed models and methods, as well as the program and methodological complex of proactive project management for the development of software systems and products, were introduced into the research work and educational process at: Odessa State Ecological University, National University “Odessa Maritime Academy” and O. S. Popov Odessa National Academy of Communications, which is confirmed by the relevant acts.