NCEES Sample Questions & Solution Problem 508

[SPSUEngineer]

Construction Afternoon Sample Question #508, Pg. 47 of 2008 Copyright Book

I don't understand how they are getting the solution for Activity G on Pg. 151.

ES = 9

EF = 11

Duration = 2 days

Shouldn't LF = 11 and LS = 9 ?

Where do they get 13 as the LF of Activity G? I think this is an error or maybe they are missing an arrow between activities G and H. I don't see any corrections for this problem in the Errata posted October '08.

 

[SPSUEngineer]

Well I figured it out after looking at the definition of late finish. This problem is a good one to study because it has some the the more advanced CPM skills in it such as FF Lag on an activity.

Late Finish (LF): The latest time an activity can finish, and still not delay the completion of the project as a whole.

In this problem, Activity H has a LF of 13 days. Therefore, the late finish of Activity G is also 13 Days since this is the latest time Activity H can finish without delaying the completion of the project as a whole. This is tricky because most problems I've seen so far end with one activity and not 2 independant activities.

 

[IlPadrino]

I think this is the same problem as we discussed in the topic CPM Method Problem...

 

[SPSUEngineer]

I see it is indeed the same problem. Thanks IlPadrino.