Activity Graph - Calculation

[solomon_13000]

I am having problems understanding how to calculate the latest start time
and the slack time. How is it calculated as shown in this website:

http://www.mutaiyas.com/activity.htm

LST - Latest start time
EST - Earliest Start Time

I have also shown my own calculation which is below the table
of the website. The only clue I have discovered is I need to
find out the longest path.


Your help is kindly appreciated.

Regards.

[pmkb]

Fundamental Scheduling Procedures - see section 10.3 for the basic procedure.