Complexity and the notion of system of systems: part (I): general systems and complexity

The paper reviews the origins of the fundamentals of the systems notion which may underpin the development of a unifying conceptual framework that explains the notion of System of Systems and supports the development of methodologies for System of Systems Engineering. The paper is organised in two parts. Part I deals with a historical review of the development of the notion of systems and then deal with the definition of its key components. The crucial notion of emergence is discussed and links with different domains, where the concept emerges are established. We attempt to identify and classify the fundamental ingredients of the notion of “system complexity”. A typical complex problem, the Integrated Manufacturing System is then considered and its multi-dimensionality and associated challenges provides a motivation for the development of a new structural approach to the definition and characterisation of the notion of System of Systems, which is undertaken in Part II.