Architecture of Complex Systems

Architecture of Complex Systems (ACS) presents an ontological framework for understanding systems as coherent architectures rather than as collections of behaviors or dynamic processes.
The work addresses a foundational question: under what conditions does a system exist as a unified entity at all?

ACS is grounded in the primacy of relational structure over observation and dynamics. Architectural truth is defined as relational and depends on coherence, closure, and invariants within a bounded relational structure. On this basis, the paper establishes a fundamental boundary: neither observational data nor knowledge of system dynamics suffices to reconstruct system ontology. Dynamics may describe state transitions and trajectories, but they do not uniquely determine architectural structure.

The paper introduces a minimal relational algebra as a working language for architectural reasoning. This algebra is used to articulate admissibility, architectural coherence, and system existence without reference to domain-specific implementations, technologies, or empirical case studies. Architecture is treated as ontologically prior to both dynamics and observation.

The contribution is intentionally foundational. The work fixes the ontological core of ACS and situates it within a broader research program concerned with discrete existence and the limits of observation. Domain-specific interpretations and applications are treated as subsequent extensions built upon this explicitly defined foundation.