Science advances, on the one hand, by developing—in depth and in breadth—the traditional disciplines, and, on the other, by creating entirely new ones. The emergence of new scientific disciplines is governed, essentially by two major factors : (1) a tendency toward specialization, and (2) a tendency toward the generalization of science. Systems science and engineering was produced by the latter tendency. An objective of this paper has been to identify the topical areas of systems science and engineering curricula and thus provide an extensional definition of its main components of concentration.