7.3 Determine Critical Paths and Float Times

Note: if you cannot remember how to apply forward and backward scanning, revise notes for 7.2 Forward and Backward Scanning.

Float Times

  • The float time for an activity is the difference between its latest start time (LST) and earliest start time (EST).
  • This represents the amount of time the individual activity can be postponed without changing the duration of the project overall.


Picture 5

Above is an activity network which has undergone forward and backward scanning to determine the EST and LST of each activity. The float times of each activity can be calculated from these values:

Read More »7.3 Determine Critical Paths and Float Times