PERT and CPM are similar diagramming techniques using network style diagrams
to show the relationship between tasks.
The significant difference between the two is that CPM uses a single
estimate for durations PERT uses a time calculation algorithm of:
(optimistic + 4 x likely + pessimistic) / 6
to determine the probable time.
Because CPM uses a single duration, it is possible to determine the path
through the network diagram that has the most amount of elapsed time. That
path is the critical path since anything that delays a task on that path
delays the completion of the project. (Note that although I have referred
to the singular path, complex projects will likely have two or three paths
that take the same maximum time so the critical path can often be plural:
critical pathS.
Project uses the Network view to show the network. I don't use it often,
but on those occasions when I do use it, I have found that it is best to
hide the summary tasks. So ...
1. Tools | Options | View-tab and clear the box labeled "Show summary
tasks"
2. View | Network Diagram
