Systems Thinking

This Knowledge Area (KA) provides a guide to knowledge about systems and systems thinking , which together form the foundations for all applications of a systems approach and applications of systems engineering . This knowledge is not specific to systems engineering (SE), but is part of a wider systems body of knowledge. We have not attempted to capture all of the system knowledge here, but to identify those aspects relevant to the Systems Engineering Body of Knowledge (SEBoK).

Topics

The topics contained within this knowledge area include the following:

Introduction

The word system is used in all areas of human activity and at all levels. But what do people mean when they use the word “system” and is some part of that meaning which is common to all applications? What is a system? Are there different types of systems? These and similar questions, all relating to the use of the word “system” in everyday language, need to be given careful consideration if we are to achieve a clear understanding of the underlying concepts of systems thinking before applying it to an engineering context.

systems thinking is an approach to understanding or intervening in systems, based on the principles and concepts of systems. In this KA we give some basic definitions of systems thinking.

general system theory (GST) (von Bertalanffy, 1968) considers the similarities between systems from different domains as a set of common systems principles and concepts.

A principle is a rule of conduct or behavior. To take this further, a principle is a “basic generalization that is accepted as true and that can be used as a basis for reasoning or conduct” (WordWeb.com). A principle can also be thought of as a “basic truth or law or assumption” (ibid).

A concept is an abstraction, or a general idea inferred or derived from specific instances. For example, by viewing a pet dog, one can infer that there are other dogs of that “type.” Hence, from this observation (or perhaps a set of observations) the concept of a dog is developed in one's mind. Concepts are bearers of meaning, as opposed to agents of meaning, and can only be thought about, or designated, by means of a name.

Principles depend on concepts in order to state a “truth.” Hence, principles and concepts go hand in hand; principles cannot exist without concepts and concepts are not very useful without principles to help guide the proper way to act (Lawson and Martin 2008).

GST tends to concentrate on the principles and philosophy behind the aforementioned idea. “Despite the importance of system concepts … we do not yet have a unified or integrated set (i.e., a system) of such concepts” (Ackoff, 1971).

Ackoff proposes a system of "system-concepts" to bring together the wide variety of concepts which have been proposed. His 30 distinct concepts are grouped under four headings, or principles, “How Systems are formed,” “How Systems Change,” “How Systems Behave,” and “How Systems Adapt and Learn.”

Lawson describes a system of "system concepts" (Lawson 2010) where systems are categorized according to Fundamental concepts, Types, Topologies, Focus, Complexity, and Roles. Hitchins defines a similar set of principles which also consider some of the issues of hierarchy and complexity of particular relevance to a system approach (Hitchins 2009).

In this KA, we provide an overview of the most important aspects of this system of systems concepts .

References

Works Cited

Bertalanffy, L. von. 1968. General System Theory: Foundations, Development, Applications, Revised ed. New York, NY, USA: Braziller.

Ackoff, R.L. 1971. "Towards a System of Systems Concepts". Management Science. 17(11).

Hitchins, D. 2009. "What Are the General Principles Applicable to Systems?" Insight 12(4).

Lawson, H. 2010. A Journey Through the Systems Landscape. London, UK: College Publications, Kings College.

Lawson, H., and J.N. Martin. 2008. "On the Use of Concepts and Principles for Improving Systems Engineering Practice". Proceedings of the 18th Annual International Council on Systems Engineering (INCOSE) International Symposium, 5-19 June 2008, Utrecht, The Netherlands.

Primary References

Bertalanffy, L. von. 1968. General System Theory: Foundations, Development, Applications. Revised ed. New York, NY: Braziller.

Checkland, P. 1999. Systems Thinking, Systems Practice, New York, NY, USA: John Wiley & Sons.

Churchman, C. W. 1968. The Systems Approach and its Enemies. New York, NY, USA: Dell Publishing.

Flood, R. L. 1999. Rethinking the Fifth Discipline: Learning Within The Unknowable. London UK: Routledge.

INCOSE. 2011. INCOSE Systems Engineering Handbook: A Guide for System Life Cycle Processes and Activities, version 3.2.1. San Diego, CA, USA: International Council on Systems Engineering (INCOSE), INCOSE-TP-2003-002-03.2.1.