Page 165 - DCAP304_DCAP515_SOFTWARE_PROJECT_MANAGEMENT

Unit 8: Network Planning Model

(or float) of four days, as well as a total slack (or float) of four days. In other words, if Notes
activity E were to be completed more than three days later than its EF date, it would delay
completion of the project. We know that if an activity has zero slack, it determines the
project completion date. If an activity with total slack greater than zero were to be delayed
beyond its late finish date, it would become a critical path activity and cause the completion
date to be delayed.

Notes Based on the method you used to compute the early and late schedules, the sequence
of activities having zero slack is defined as the critical path. If an activity has been date-
constrained using the on-this-date type of constraint, it will also have zero slack. However,
this constraint usually gives a false indicator that an activity is on the critical path. Finally,
in the general case, the critical path is the path that has minimum slack.

Self Assessment

Fill in the blanks:
5. ………………. are numbered sequentially, and the sequential ordering had to be preserved,
at least in the early versions.

6. Each activity in the network diagram is represented by a rectangle that is called an
………………. node.

7. A ……………….. is simply a relationship that exists between pairs of activities.
8. The type of dependency that describes the relationship between activities is determined as
the result of ………………….. that exist between those activities.
9. …………………… dependencies between activities arise when one activity (the successor)
requires output from another (the predecessor) before work can begin on it.

10. ………………… (also called float) is the amount of delay expressed in units of time.

8.3 Analyzing the Initial Project Network Diagram

After you have created the initial project network diagram, one of two situations will be present:

 The initial project completion date meets the requested completion date. Usually this is
not the case, but it does sometimes happen.
 The more likely situation is that the initial project completion date is later than the requested
completion date. In other words, we have to find a way to squeeze some time out of the
project schedule.

8.3.1 Compressing the Schedule

In situation where, the initial project completion date is later than the requested completion
date, you must find ways to reduce the total duration of the project to meet the required date.
What you will now have to do is adjust and readjust the critical path. This is known as schedule
compression. By making adjustments to when tasks begin or by adding additional resources, you
can complete the same work in less time.

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