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 : 

Task    -   Preceding Activity   -   Estimate in month

Start                  -                                    0

1                       Start                               3

2                        1                                   4

3                        Start                               2

5                        3                                    5

4                        Start                               7

5                        4                                   1

End                    2                                  3

End                    5                                   4

If you look on the left side, you will see by example that the Task 5 is there twice,  with two different Preceding ACtivity, means that there is a path convergence, that's fine !!   BUT,   there is also an Estimation for both Task 5, because here, in that kind of CPM diagram, the time is associate Between the Activity

Between Activity 3  And Activity 5, it take 5 months

Between Activity 4  And Activity 5, it take 1 month

I am comfortable to draw the diagram with that board, but I am not really comfortable to do the Forward and Backward Path

My question here is, do you have any recommendation for this kind of type of CPM, on how to do Forward and Backward Path

Also,

Which Type we will see at the Exam