Page 225 - E2 Integrated Workbook STUDENT 2018

Project management tools and techniques

 Calculate the Latest Event Times (LET)

Work right to left. Start at the last node: the LET of the last node must equal the EET
of the last node, so here the LET of the last node is 26. You then look at each activity
in turn.

Take the LET from the node at the end of the activity line, and deduct the duration of
the activity. The answer gives you the LET for the node at the beginning of the
activity line.

When you have a choice for the LET, you always use the lowest.

This completes the network diagram – now you can put in the node reference
numbers and identify the critical path.

8
2
A B
8

8 10
0 18 E 26
1 4 5
0 18 8 26

C D

6 4
6 3
14

The network diagram shows us 3 important things about the project:

 The critical path is ABE – these activities must be done on time

 The overall duration of the project is 26 weeks

 Activities C or D have slack of 8 weeks.

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