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Towards a System of Systems Concepts Author(s): Russell L. Ackoff Source: Management Science, Vol. 17, No. 11, Theory Series (Jul., 1971), pp. 661-671 Published by: INFORMS Stable URL: http://www.jstor.org/stable/2629308 . Accessed: 08/08/2011 20:33
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MANAGEMENT SCIENCE Vol. 17, No. 11, July, 1971 Printed in, U.S.A.

TOWARDS A SYSTEM OF SYSTEMS CONCEPTS*
RUSSELL L. ACKOFF University of Pennsylvania The concepts and terms commonly used to talk about systems have not themselves been organized into a system. An attempt to do so is made here. System and the mostimportant types of system are defined so that differences and similarities are made explicit. Particular attention is given to that type of system of most interest to management scientists: organizations. The relationship between a system and its parts is considered and a proposition is put forwardthat all systems are either varietyincreasing or variety-decreasing relative to the behavior of itsparts.

Introduction
The concept system has come to play a critical role in contemporary science.' This preoccupation of scientists in general is reflected among Management Scientists in particular for whom the systems approach to problems is fundamental and for whom organizations, a special type of system, are the principal subject of study. The systems approach to problems focuses on systemstaken as a whole, not on their parts taken separately. Such an approach is concerned with total-system performance even when a change in only one or a few of its parts is contemplated because there are some properties of systems that can only be treated adequately from a holistic point of view. These properties derive from the relationships between parts of systems: how the parts interact and fittogether. In an imperfectly organized system even if every part performs as well as possible relative to its own objectives, the total system will often not perform as well as possible relative to its objectives. Despite the importance of systems concepts and the attention that they have received and are receiving, we do not yet have a unified or integrated set (i.e., a system) of such concepts.Different terms. are used to refer to the same thing and the same term is used to refer to different things. This state is aggravated by the fact that the literature of systems research is widely dispersed and is therefore difficult to track. Researchers in a wide variety of disciplines and interdisciplines are contributing to the conceptual development of the systems sciences but these contributionsare not as interactive and additive as they might be. Fred Emery [3] has warned against too hasty an effort to remedy this situation:
It is almost as if the pioneers [of systems thinking], while respectfully noting each other's existence, have felt it incumbent upon themselves to work out their intuitions in their own language, for fear of what might be lost in trying to work through the languageof another. Whatever the reason, the results seem to justify the stand-offishness. In a short space of time there has been a considerable accumulation of insights into system dynamics that are readily translatable into different languages and with, as yet, little sign of divisive schools of thought that for instance marred psychology during the 1920s and 1930s.Perhaps this might happen if some...