The next step is to determine the earliest time each task can be started and the earliest time each task can be finished. We will call these Early Start (ES) and Early Finish (EF) times. The diagram with these times are shown here. The resultant schedule is called an early start schedule. network-diagram-with-early-start-and-early-finish-times1x
Make sure you follow the steps involved in determining the ES and EF for each task. For the network diagram, it is obvious that the expected duration of this project is 21 weeks. Of course, this assumes availability of all needed resources and accurate estimation of task durations. See what Dilbert thinks. LWF1
Next we determine the Late Finish (LF) and Late Start (LS) for each task by working our way backwards through the network diagram. The result with explanations are shown here. The resultant schedule is called a late start schedule. Again, make sure you understand the steps involved in determining the LF and LS times for each task.network-diagram-with-late-start-and-late-finish-times1x
Continue to the next unit to find out how we use what we have learned so far to determine the critical path for this simple project.