According to Flood & Carson’s Dealing with Complexity, Systems Thinking –as deriving from the understanding of biological behavioral sciences and the systems that describe them –is a “framework of thought” whereby complex and seemingly unpredictable or unforeseeable object-behavior can be made understandable through the use of Systems methodologies, concepts, and principles in real-word situations (e.g. “problem solving”). Grasping these core concepts helps in the planning of complex information systems because they essentially reshape the way one reads or understands complexity and designs for complex adaptive systems. The characteristics of a system represent both “an organized whole” and an aggregate of parts (or elements) that interact with one another through flows of exchanges of “materials, information, or energy”. Understanding a system as part of a larger context (where the surrounding environment feeds back into it and affects the way the system behaves) is also a very important concept that enables us, as designers, to take context into account and consider the possible or potential futures of our proposed system whereby it might evolve, learn, change, and preferably adapt to contextual occurrences or events by identifying the extent or area of probabilistic affect (emergent property).
Systems Thinking teaches us how the design of a complex information system often needs to include mechanisms to account for “short term” and “long term” (or chronic) disturbances of flow caused by environmental changes, by dealing with the “whole” system rather than its parts. By creating systems able to adapt to environmental changes and thus to learn to sustain themselves in the face of unforeseen shifts, design can plan for more effective and efficient complex information systems. This is depicted primarily in the study of Cybernetics. Negative Feedback describes the “parameters” of a self-sustaining system; that is to say, a set of control systems within a larger given system that help enact a balance overtime of the system’s dynamics. Positive Feedback, however, describes the growing mutation of a system, often seen as an increase of disturbances and an imbalance of “elements” or component ratio that lead to a total collapse of a system when Negative Feedback no longer intervenes. A “variety” of both Negative and Positive Feedback seem to be necessary for the survival and balance of complex systems (“the law of requisite variety”(Ashby, 1956)).
According to the authors, Feedback represents the impact of an element over other elements of a given system and how this impact is then feed back into the system (Flood, 1993:8). From this inherent behavior emerge the distinctions made between closed and open systems. On the one hand, a Closed System (e.g. a machine) is identified by a system that interacts only with its subsystems and feeds back information and energy amongst itself. This kind of system discerns itself from the environment in which it lives; such as a machine will respond to its own coded rules regardless of its surrounding context. On the other hand, an Open System evolves and interacts with its environment in addition to its relationship with itself. For instance, an organism will sustain itself through both relationships within its inner biological mechanisms and its outer exchanges with the environment in which it lives, and will adapt to contextual bifurcations as it changes and evolves overtime. If an organic system were to ever be so-called closed, environmental disturbances may cause the system to become unbalanced and might have dire consequences on the state of the system by rendering it dysfunctional. An organism will appear to be unchanged overtime (as a whole) although its “information, materials, and energy” will have changed in the process of exchanging and interacting with its environment.
Homeostasis describes the condition whereby a system or organism is “open” to in/out fluxes. Homeostatic systems can be said to be self-sustaining; that is, such systems sustain themselves through equally balanced exchanges of inputs and outputs over time. As an analogy, I had an accident almost 10 years ago that injured my knee and resulted in a series of surgeries that led to subsequent procedures involved in the regeneration of the inner tissues, the superficial healing of the skin, and the rehabilitation of the muscles to walk comfortably as I used to. I understand the healing of a wound as being a Homeostasis experience. Although this may take at times longer than other times, the body regenerates its tissues in quite beautiful and surprising ways through both in/out exchanges (medication, food, physical therapy, dermatological applications, etc.). The body remains a balanced system as its inner parts fight against external events (e.g. germs) and yet requires its environment to sustain itself and grow stronger and fitter. This sub-system (here, the knee) remains seemingly unchanged whilst its materials or information are always in flux.
Flood, Robert L. and Ewart R. Carson. “Systems: Origin and Evolution, Terms and Concepts” Dealing with Complexity: An Introduction to the Theory and Application of Systems Science. 1993: pp. 1-21