Exploring Similarities Between Systems: Concepts, Properties and Implications

Similarity is ubiquitous in the world and essential for understanding both theoretical and practical aspects of systems. This study explores the concepts, properties and implications of similarity across natural and artificial systems. Similarity, defined as a comparative relational property grounded in the overlap or closeness of properties of two or more entities, is characterized by systematicity, comparability, hierarchy, degree, dynamism, adaptability, causality and relativity. Based on these, this study provides new insights into systems science from the system similarity perspective. We explore how similarity influences system structure, function, behaviour and evolution through five principles: system similarity principle, similarity configuration principle, similarity synergy principle, similarity adaptation principle and similarity dynamic balance principle. Overall, this study proposes the system similarity theoretical framework that reveals fundamental laws of similarity among systems, which establishes a unified foundation for interdisciplinary systems research and enhances practical approaches to addressing complex problems.