The systems sciences: What are they? are they one, or many?

Abstract What is the significance of the recent appearance of new Institutes, Departments, and even Schools bearing the name ‘system science?’ What relationship might this new discipline have to established systems-level specialties like operational research? This article argues that the four major domains of the systems approach and their products are regions in a single spectrum that might be usefully considered ‘the systems sciences’. The spectrum is described using a dozen characteristics that show gradual, continuous variation across the domains and therefore might serve as pathways for information transfer and cross-fertilization, as well as a descriptor of what the domains might contribute to each other. An overview of the potential ‘special knowledge’ of systems science and a ‘morphology’ of the 33 established fields involved is presented. The use of the terms ‘systems’ and ‘science’ in the phrase ‘systems sciences’ is critically examined and the systems sciences are described as a ‘meso-science’ like some of the biological sciences. Finally, possible interconnections between the long-term futures of general systems science and operational research are considered.