Compact modeling is a methodological approach focused on developing simplified, computationally efficient mathematical representations of complex physical phenomena or systems. As a research concept, it investigates methods for abstracting the essential behavior of intricate structures or processes into models suitable for practical simulation, analysis, or design within larger systems. Its significance lies in enabling the feasible study and engineering of complex systems, such as electronic circuits or, as informed by the provided context, potentially complex nuclear processes or reactor components, where highly detailed physical models are computationally intractable or unnecessary for system-level applications.