Approaches to constructing project management systems relatively used standards were investigated. Advantages and disadvantages of each approach were identified. The main principles, underlying the project management system operation were formulated. As a result of studies, it was found that the mutual adaptability of the project management system and the enterprise management system was underinvestigated. As one of the principles of constructing composite management systems, the adaptability principle was outlined. The concept of bi-adaptability was introduced. The definition of bi-adaptability as the property of adaptability implementation in two ways was given. The definition of the bi-adaptive management system of the project-oriented enterprise was presented. The methodological, information and organizational tools to ensure bi-adaptability were considered. As an element base of adaptability implementation, frames were proposed. The advantages of this approach were described. The definition of structurally-producing approach to constructing the bi-adaptive management system was given. The fundamental tasks of the bi-adaptive management system of the project-oriented enterprise were formulated. The scientific task of constructing the bi-adaptive management systems of the project-oriented enterprise was set. The proposed approach to constructing such systems based on frame models will allow to build a more effective management system of the project-oriented enterprise through introducing a better mechanism of its adaptation to changes in the internal and external environment.