Project management is a complex process which is governed by project management methodologies, standards and other regulatory requirements. This process is supported by project management information systems, which could be configured according to requirements of particular methodologies represented in a standardized manner. This standardized representation is based on a comprehensive project management domain model. However, existing conceptualizations of the project management domain have limited scope. Therefore, this paper proposes to elaborate a comprehensive conceptual model of the project management domain to be used for development of XML schema for configuration of project management information systems. Development of the comprehensive concept model is based on analysis and integration of existing conceptualizations of project management and conceptual model integration. Four existing conceptualizations are integrated, and the integrated project management domain concept model incorporates data, process and knowledge related entities.