工程是人类有组织、有计划、有目的地利用各种资源和基本经济要素构建和制造人工实在的活动,是直接生产力。工程是在特定的自然和社会条件下，相关技术群和诸多基本经济要素组合-集成在一起的动态系统。其中，技术集成系统体现着相关、但又功能不同的异质技术群（不同的技术模块），通过动态有序的集成过程所形成的特定结构及其动态运行的方式；而且这一特定的技术集成系统必须要与特定的自然、社会条件下诸多基本经济要素的合理配置（如资源、土地、资本、劳动力、市场、环境等）互相协同作用，通过设计、构建和运行，形成工程系统，并产生特定的、预期的功能和价值。工程与科学、技术、产业有着密切的联系,但又有所不同。对经济及其结构而言，工程是微观单元，产业是中观层次单元，而由不同产业构成的产业结构则处于宏观层次。工程是不断演化的，工程演化推动着产业的发展和产业结构的调整，甚至出现产业革命。

Engineering is a human activity to construct and create artificial entity in a well-organized, planned and purposeful way by means of various resources and basic economic elements. Engineering is the direct productivity .Engineering is a dynamic system which is combined and integrated with related technology groups and a crop of basic economic elements under certain natural and social conditions. Technology integration system embodies the specified frame and dynamic operating ways formed by the dynamic and ordered integrating process of related but varied heterogeneous technology groups. This system must be allocated properly to and has a harmonious interaction with basic economic elements under certain natural and social conditions, such as resource, labor, land, capital, market and environment, and so on. They will form an engineering system and produce the specific and desired function and valued by being designed, constructed and operated. Engineering has the close relation but some difference with science, technology and industry. From the point of economy and its structure, engineering is the micro-unit, industry is the meso-unit, and industrial framework which is made of different industries is the macrounit. Engineering is evolving constantly. The engineering evolution propels forward the industrial development and the adjustments of industrial framework, even if the appearance of industrial revolution.