Page 235 - DMGT521_PROJECT_MANAGEMENT

Project Management

Notes

Task Describe the steps for Drawing the PERT/CPM Network.
The Backward Pass - Latest Finish Time Rule

To make the Backward Pass, we begin at the sink or the final event and work backwards to the
first event.

Figure 13.13: Backward Pass and Latest Finish Time Rule

At Event 3 there is only one activity, Activity 3-4 in the backward pass, and we find that the value
is 11-7 = 4 weeks. However at Event 2 we have to evaluate 2 activities, 2-3 and 2-4. We find that
the backward pass through 2-4 gives us a value of 11-6 = 5 while 2-3 gives us 4-0 = 4. We take
the smaller value of 4 on the backward pass.
Self Assessment

State True or False:
14. Planning, Scheduling and Control are considered to be advanced Managerial functions.
15. There are many variations of PERT/CPM which have been useful in planning costs,
scheduling manpower and machine time.
16. Non-critical activities can be replanned, rescheduled and resources for them can be
reallocated flexibly.
17. Each activity in a PERT/CPM Network is represented by a circle symbol.

13.9 Tabulation and Analysis of Activities

We are now ready to tabulate the various events and calculate the Earliest and Latest Start and
Finish times. We are also now ready to compute the SLACK or TOTAL FLOAT, which is defined
as the difference between the Latest Start and Earliest Start.

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