The textbook gives consideration to the conceptual general theory of systems, classification of systems and their models, methodology of modeling, system functioning and development analyses. There have been identified the principles of designing, construction and optimization of systems. The analysis was made of system decision-taking methods applied in intricate problem situations. The textbook is intended for students and postgraduate students who take a course of training in specialties of group 6.1004 “Transport Processes” at institutions of higher education.