Overhaul project refers to the project that involves or replaces some major components or equipment, but does not need to be completely dismantled. Medium repair project refers to a project that needs to move or dismantle a small amount of main structures or equipment, but maintains the structure and scale of the original building (or equipment). Minor repair works refer to routine maintenance works that can ensure the original damage degree of the house (or equipment) even if minor repairs are made to the parts of the house (or equipment) during use.