Systems theory and systems engineering

The main features of systems theory are presented. The systems approach comprises a body of concepts for the description, analysis and design of complex entities. It embraces the engineering of control, computing systems, biological organisms, human organisation and economics. The generalised theory has the feature of holism, `the whole is greater than the sum of its parts´. Complex entities are decomposed into simpler components, handled separately, and then recombined in formal models, and as analogies between diverse systems that show similarity of structure and of dynamic behaviour