The article presents the author's approach to building a gnoseological model of project management research from a system approach. The aim of the article is to form the conceptual principles of the theoretical and methodological basis for the analysis of project management processes based on axiomatic conditions of consistency. The methodological basis of the research was the theses of classical and modern economic theory and the research work of domestic and foreign scientists on project management issues. The author's methodological concept is based on the unification, within a systematic paradigm, of the Marxist school of political economy and the principles of the institutional trend. The basic hypothesis of the research was the assumption that it is possible and expedient to use a descriptive methodology for identifying systems to requests for managing investment projects as open systems. Statement of the basic material. Methodological analysis has shown that the system is an integrity which is capable of self-development, formed by a sufficient set of elements that are able to reproduce themselves and function relatively independently, united by a network of significant structural, genetic and subordinate links. In the analysis of investment projects, the content of these links is presented through the investment legal relationship. From the point of view of the system paradigm, an investment project can be regarded as an organisational, financial and technically conditioned integrity, formed by a sufficient set of elements (property, property rights and other values) capable of self-reproduction and united by an investment legal relationship that establishes structural and subordinate relationships. It has been proved that the circulation area is a necessary and sufficient condition for the integrity of investment projects, transforms individual capital into public capital and ensures its circulation and reproduction. Also, the axiomatic condition of unity for investment systems is implemented through a set of formal and informal rules (laws) of composition. Originality and practical relevance of the research. The theoretical and methodological concept has theoretical significance and can be transformed into an appropriate applied toolkit for developing scientific and practical recommendations for project management. Conclusions and prospects for further research. The conceptual theoretical and methodological basis for the analysis of project management processes based on axiomatic conditions of consistency allows us to define the system triad of an investment project and formally identify the basic system components. Further research will focus on the development of instrumental and methodological support for project management.