System

An organized set of interacting components forming a coherent whole, with identifiable boundaries separating it from its environment. The fundamental unit of analysis in systems science.

Formal Definitions

Mobus & Kalton (2015):

“A system S is a 7-tuple: S_{i,l} = ⟨C, I, Δ, N, G, B, T, H⟩ where C is composition, I is interfaces, Δ is transformations, N is network structure, G is governance, B is boundary, T is time scale, and H is history. The indexes i and l denote subsystem position and level of organization in the system-subsystem hierarchy.”

(Principles of Systems Science, Section 4.3)

“Bounded networks of relations among parts constitute a holistic unit. Systems interact with other systems, forming yet larger systems. The Universe is composed of systems of systems.”

(Principle 1: Systemness, Section 2.3)

Bunge (1979):

“Let T be a nonempty set. Then the ordered triple σ = ⟨C, E, S⟩ is a system over T iff C and E are mutually disjoint subsets of T (C ∩ E = ∅), and S is a nonempty set of relations on the union of C and E.”

(A World of Systems, Chapter 1)

Synthesis

Both formalizations agree systems are relational structures defined by composition, environment, and the relations among them. Mobus extends Bunge’s minimal set-theoretic formulation with temporal dynamics (T), history (H), governance (G), and transformations (Δ) — elements necessary for modeling real-world complex adaptive systems.

Explore Further

  • Boundary — defines what’s inside vs outside
  • Environment — the system’s context
  • Emergence — properties the whole has that parts lack