Early and Late Event Times
Activitiy times
- Activities within a project typically take different lengths of time to complete
- The early event time is the earliest time of arrival at the event, allowing for the completion of all preceding activities.
- The late event time is the latest time that the event can be left without extending the time needed for the project.
- The early event times are calculated starting from 0 at the source node and working towards the sink node. (forward scan/pass)
- The late event times are calculated starting from the sink node and working backwards towards the source node. (backward scan/pass)
- If there is no float for an activity then it is considered a critical activity.
The forward pass
- On the forward pass, we take the maximum value possible of the arcs going into the target node.
The backwards pass
- On the backwards pass, we take the minimum possible value of the arcs going into the target node.