4、 When the construction period is urgent, the construction period early warning system must be established in the way of "countdown", under the guidance of "large rolling, large flow and dynamic management", and in the mode of "two-level network, five level plan" hierarchical management. The basic points are to take the mandatory plan proposed by the owner as the premise, the primary network as the goal, the image control as the framework, and the sub network as the guarantee, Make up for small flow