Systems Theory

An open system exchanges matter, energy, and information with its environment and depends on this exchange for its existence, while a closed system is isolated from its environment. Most real-world systems are open systems that maintain themselves through continuous interaction with their surroundings.

The phenomenon whereby complex patterns, properties, or behaviors arise from the interactions of simpler components in a system, but cannot be predicted or explained solely by analyzing those components in isolation.

Circular causal pathways in which the output of a system is routed back as input, influencing future behavior. Negative feedback reduces deviation and promotes stability, while positive feedback amplifies deviation and can drive exponential growth or collapse.

The tendency of a system to regulate its internal conditions to maintain a stable, relatively constant state of equilibrium, even in the face of external disturbances. Homeostasis is achieved primarily through negative feedback mechanisms.

The principle that in open systems, the same final state can be reached from different initial conditions and by different pathways. Unlike deterministic closed systems, open systems are not rigidly bound by their starting point.

Entropy is the tendency toward disorder and energy dissipation in systems (from thermodynamics). Negentropy (negative entropy) is the process by which open systems import energy and information from the environment to maintain or increase their internal organization.

Systems are organized into levels where each level contains subsystems that are themselves systems (holons). A hierarchy describes the nesting of systems within larger systems, while a holarchy emphasizes that each element is simultaneously a whole and a part.

Places within a complex system where a small change can produce large effects on the system's behavior. Identified by Donella Meadows, leverage points range from relatively weak (adjusting parameters) to extremely powerful (changing the system's goals or paradigm).

A concept developed by Maturana and Varela describing a system that is capable of reproducing and maintaining itself by continuously creating its own components. Autopoietic systems are self-referential and define their own boundaries.

The principle that a system's internal regulatory mechanisms must be at least as complex as the disturbances it needs to handle. Only variety can absorb variety, meaning a controller must have as many possible states as the system it controls.