Engineering concept refers to the fundamental principle or idea on which an engineering system or design is based. Synonyms for engineering concept include engineering theory, principle, framework, model, approach, doctrine, methodology, system, and paradigm. An engineering theory is a hypothesis or set of hypotheses used to explain the behavior of an engineering system or design. A principle is a fundamental truth or assumption that serves as a foundation for an engineering system or design. A framework is a structure that provides a framework for a set of engineering concepts or principles. A model is a simplified representation of an engineering system or design used to explain or predict its behavior. An approach is a proposed method for solving an engineering problem. A doctrine is a set of principles or beliefs that guide an engineering system or design. A methodology is a systematic approach to solving an engineering problem. A system is a collection of interrelated elements that work together to achieve a common goal.