Discover Systems Theory: Easy Basics to Exciting Uses

Owen Robert McGregor
3 min readOct 23, 2023


System Theory is the Transdisciplinarity study of Systems, while Systems Thinking is about understanding Systems.

What is a System?

A System is a group of interdependent and interrelated components to form a unified whole, which is either natural or human-made. Every System is defined by its boundaries, structure, functions, behaviour and inter-connectivity. Expressed through its relations with other Systems through its synergy or emergent behaviour.

Defining what is a System

Because Systems Theory views the world as a complex network of interconnected components, boundaries are used to determine what the System is in context and the subject of study, and what is a part of the surroundings.

The components of a System must be related; “designed or act to work as a coherent entity”, otherwise they would be two or more distinct Systems.

Determining the Type of System

The type of System is determined by its relationship with its surroundings, the nature of its design, and interactions with other Systems.

  • Open Systems. Exchange matter and energy with its surroundings.
  • Closed Systems. Exchange energy, but not matter with its surroundings.
  • Isolated Systems. Exchange neither matter nor energy with its surroundings.
  • Natural Systems. Where the System doesn’t have an apparent objective but its behaviour can be interpreted as purposeful by an observer.
  • Human-made Systems. Where the System was created with an objective, with various purposes to achieve an action to be performed by or with the System.

Lastly, if a System is Active or Passive.

  • Active. Where the components and structure of a System, interact in behaviours or interrelate through a contextual boundary (Dynamic).
  • Passive. Where the components and structure of a System, are being processed but give rise to no behaviours or interrelate through a contextual boundary (Static).

Modelling a System

Modelling a System comprises of multiple views, such as; Concepts, Implementation, Development, Structure, Behaviours, and Inputs and Outputs of data. Within the boundaries of the System, all components and Sub-Systems would be defined. Demonstrating a model of a System will take the form of a Systems Architecture and an Architecture Description.

  • System Architecture is a conceptual model that defines the structure, and behaviour, through multiple different views of the System.
  • Architecture Description is a formal description and representation of a System which supports reasoning about the structure and behaviours of the System.

Black Box

The term Black Box is used to describe a System, in which the process or collection of processes which turns inputs into outputs, is unobservable or incomprehensible, either by design or as an inherent trait of the System,


A Sub-System is a set of components which is a System in of itself and is a component of a larger System.

Application of Systems Theory

Systems Theory is about developing concepts and principles. This is done by modelling its dynamics, constraints, conditions, and relations. To answer the purpose of its design, and methods and tools being deployed.

Its inherent value is in finding broadly applicable concepts and principles which can be applied across disciplines, hence why it’s Transdisciplinarity. By discerning and applying these concepts and principles to other Systems at each level of nesting in a wide range of fields, a greater degree of optimised equifinality can be achieved.

Additionally, it is used to conceptualise and understand a System. Which is usually deployed in several disciplines, such as;

  • Enterprise Modelling
  • Software Engineering
  • Systems Engineering
  • Systems Science
  • Social Systems

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Owen Robert McGregor

Economics Prodigy from Melbourne 🇦🇺 Globe-trotting nomad 🌍 Obsessed with becoming a Modern-day Polymath 🧠 Follow for a curated list of my insights💡