Guys,

I saw two different kind of graphic ofr CPM.

Type 1

One type ( from Rita book ) by example, where you the time is associated with an activity.

Example :

Activity A Duration is 2 days.

this type is easy to understand and easy to calculate Forward / Backward Path

Type 2

Another Type that I saw in PMStudy, where The time is actually not associated to the Activity but "Between The Activity"

Example :