Calculating EST and LFT

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Created by
izzy

Cards (8)

  • Once a diagram has been completed, work forward to calculate the EST
  • The EST in the first node is shown as zero
  • For subsequent activities, the EST is found by adding the sum of the durations that leads up to the node that represents the start time of that activity
  • LFT can be calculated by working backwards from right to left to calculate the LFT
  • The LFT in the final node must equal the EST because the final activity must be on the critical path
  • The LFT is calculated by working from right to left, deducting the duration of activity in order to calculate the LFT of the previous activity
  • ESTs are calculated in exactly the same way as before, the only exception is if there is more than one path to a node, the highest total is taken as the EST
  • LFTs are calculated in exactly the same was as before, the only exception being is if there is more than one path to a node, this time the lowest total is taken as the LFT