Abstract: Based on the analysis of activity floats existed,three new concepts of float are proposed,intrinsic relation of the same activity's float is offered,and label algorithm is given,moreover,floats transitivity of different activities is computed. In allusion to the initial scheme of the problem of resource leveling,we protract the initial scheme stochastically. It is flexible and applicable for network planning.On the basis of activity float transitivity,the optimal scheme of the resource leveling problem is studied. Furthermore, considering the label algorithm,the proposed optimal adjusting mode is feasible and easy through example.

Key words: activity float, resource leveling, time-scaled network diagram