Relational Alignment in Multi-Node Systems: Coherence as a Property of Interaction, Not Individuals

This paper presents a methods-level framework for analysing coherence in multi-node systems using a relational rather than node-centric framing. Coherence is defined as a property of interaction between nodes, emerging through relational alignment over time rather than through local stability, optimisation, or balance at the level of individual components. The paper develops a structural account of coherence grounded in interaction patterns, local modulation, and neighbour influence. It distinguishes coherence from synchrony, convergence, and consensus, and treats stability as dynamic alignment under ongoing variation rather than as stasis or equilibrium. The framework is descriptive and deliberately constrained. It does not propose control laws, optimisation strategies, predictive models, empirical validation, or applied interventions. Its purpose is to clarify how coherence is maintained or lost through interaction structure, and to provide a rigorous methods-level lens for analysing system behaviour that is not captured by node-level metrics. This work is situated at the systems theory and methods layer and is intended to be read independently of applied or domain-specific implementations.