Abstract: In the traditional model of network planning, when all the immediate predecessor activities come to an end, the current activity can start in no time. But in the real practice, a large quantity of activities will be restricted by the start time, seldom activities can start at any time under the satisfaction of meeting the precedence relations constraints. Network with time-constrained is a very good description of these issues. The main objective of this paper is to study how float characteristics of different activities in the network change under the time-constrained. Based on the previous work, the time parameter of activities in network can be changed from traditional algorithm into time parameter with time-constrained. Finally, the differences between traditional network and network with time-constrained are analyzed. The analysis results reflect the practical value of the time-constrained model.

Key words: network planning technique, time-constrained, float