Construction & Surveying

The longest continuous chain of dependent activities through the network, which sets the project's minimum duration; activities on it have zero total float.

EF = ES + duration, where ES (early start) equals the maximum EF of all immediately preceding activities.

LS = LF − duration, where LF (late finish) equals the minimum LS of all immediately following activities.

Total float = LS − ES = LF − EF; the amount an activity can be delayed without delaying overall project completion.

Free float is the delay available without delaying the early start of any succeeding activity; it is always less than or equal to total float.