A network diagram is a flow chart that maps out the tasks and dependencies in a project. It shows the logical sequence and relationships between activities, and identifies which tasks must be completed before others can begin. To create a network diagram, all the project activities are identified and arranged in their proper sequence, with predecessor tasks linked to successor tasks with arrows. The diagram makes the critical path and parallel tasks visually clear. While helpful for planning complex projects, network diagrams can become unwieldy for large projects and take time to develop.

1. Network Diagrams

2. Introduction to Network Diagrams
▪ A network diagram is a flow chart of all tasks which make up a
project
▪ The chart demonstrates how each task relates to another
▪ Provides a logical flow of events
▪ Commonly used
▪ Network Diagrams are made up of a collection of task
dependencies known as Network Logic i.e. some tasks are
dependent on others

3. Creating Network Diagrams
1. Determine the activities which need to be completed
2. Put these activities into sequence
3. Calculate how long each activity should take
4. Establish dependencies i.e. tasks which depend on the
completion of a previous task
5. Establish which tasks are to be completed first, any tasks
with no predecessors can start as soon as the project
begins

4. Drawing the Network Diagram
1. Begin drawing the diagram by drawing the relationship between the project start and
the first activity with no predecessor
Start
T=0
AcActivity 1
T=x
2. Then find all activities which have activity 1 as a predecessor
3. Draw boxes to represent these activities, and draw arrows from activity 1 to these
activities
4. Repeat these steps for the remaining activities
5. After adding all the activities to the diagram, draw a box to represent End, and draw
an arrow from the last activity you have to complete to that box

5. Sample Network Diagram

6. Sample Network Diagrams

7. Network Diagrams
▪ Establish which tasks must be completely
individually and which can be completed
simultaneously
▪ Completing tasks simultaneously can shorten the
length of the project

8. Benefits of Network Diagrams
▪ Easy to read and understand
▪ Clearly highlights the sequence of tasks in the
project
▪ Conveys parallel activities
▪ Demonstrates the links between each task
▪ Highlights which activities are critical
▪ Shows where float can exist

9. Disadvantages of Network Diagrams
▪ The can become very complex for large projects with many activities
▪ They can be time consuming to produce
▪ Can be costly to produce
▪ Tasks may be missed out, affecting the whole diagram

10. Video Example
▪ This video shows how to draw a network diagram from a Work
Breakdown Structure
▪ In addition it shows how to calculate project task durations and
provides another example of the Critical Path Method
▪ http://www.youtube.com/watch?feature=player_detailpage&v=URdx
hl_8qIE

11. Further Reading
▪ Schwalbe, K. (2008). Introduction to project
management. Cengage Learning, 2nd ed. – Chapter
4

12. References
▪ Holland and Holland Eterprises LTD, 2013. The Network Diagram - bringing order
to project work flows. [Online] Available at: http://www.successful-projectmanagement.com/network-diagram.html [Accessed 07/11/13]
▪ Rick A. Morris, 2013. The Network Diagram- Project Management. [Online]
Available at: http://www.netplaces.com/project-management/creating-theschedule/the-network-diagram.htm [Accessed 07/11/13]