Unit project. Unit project is an integral part of a single project. It refers to a unit project that cannot independently exert its production capacity or benefit, but has independent construction conditions and can form independent use functions. According to the different nature of the project content in a single project, the part that can independently organize construction and prepare the project budget is divided into several unit projects. For example, a single mine project is divided into vertical shaft, inclined shaft and copper mine, roadway, coal bunker, ventilation safety facilities, underground track laying and other unit projects, so underground track laying in coal mines belongs to unit projects.