Systems analysis is a methodology for solving complex problems of a large scale: choosing the direction of development of firms, choosing the type of weapons, determining policies in the field of resource development, etc. A small, laconic but ideas-filled book by S. Optner, head of a large research laboratory in the USA, gives a fairly complete and clear idea of ​ ​ system analysis. It contains a description of business problems, a description of the essence of systems and a methodology for solving problems. This book was one of the first books published in the USSR covering the state of this area in the USA in the 60s, but still retains its significance. The book will be useful to heads of departments, enterprises and administrative units, economists, engineers-developers of industrial and technical systems of all industries, specialists in organization and management, including specialists in machine (automated) control systems. She will also be of interest to cybernetics and mathematicians, philosophers and sociologists.