Network Diagrams

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

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

Drawing the Network Diagram1. Begin drawing the diagram by drawing the relationship between the

project start and the first activity with no predecessor

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

StartT = 0

AcActivity 1T = x

Sample Network Diagram

Sample Network Diagrams

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

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

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

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=URdxhl_8qIE

Further Reading

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

References

▪ Holland and Holland Eterprises LTD, 2013. The Network Diagram - bringing order to project work flows. [Online] Available at: http://www.successful-project-management.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-the-schedule/the-network-diagram.htm [Accessed 07/11/13]