Network Diagrams

A network diagram is a graphical representation of a project’s schedule used in project management.
It shows the sequence of tasks, their interdependencies, and the critical path of the project.

Uses and Benefits

Network diagrams facilitate visualising how tasks are linked and depend on one another, allowing for efficient scheduling and planning.
They help identify the critical path in a project, which is the sequence of tasks that must be completed on time for the project to meet its deadline.
Being able to view the critical path can enable better risk management as it highlights where delays could have a ripple effect on the project timeline.
Network diagrams can aid communication and collaboration by making the project’s schedule easier to understand for the team and stakeholders.

Types of Network Diagrams

There are two main types: the Activity Network Diagram (AND) also known as an arrow diagram, and the Precedence Diagram Method (PDM) also known as a node diagram.
An AND uses arrows to represent activities and nodes to represent the points before and after the activity takes place.
In contrast, a PDM represents activities as nodes and dependencies as arrows between the nodes.

Creating Network Diagrams

When creating a network diagram, you should start by identifying all tasks, their dependencies, and the duration of each task.
Dependencies can be classified as finish-to-start, start-to-start, finish-to-finish, and start-to-finish, dependant on when one task needs to start or finish in relation to another.
After defining tasks and dependencies, you organise them in a flowchart format that clearly shows the sequence and interdependencies of tasks.
The critical path is the sequence where there is no slack time. If any task on this path is delayed, it will cause the whole project to fall behind schedule.

Pitfalls to Avoid

Ensure you have identified all tasks and their interactions. Missing out on any task or their dependency can lead to incorrect identification of the critical path.
Avoid overcrowding the diagram. Too many tasks or dependencies in one diagram can make it difficult to read and understand.
Be careful not to rely entirely on the diagram. Regular review and updates are necessary as project circumstances change. After all, a network diagram is only as accurate as the data it is built on.

A well-constructed network diagram is a powerful tool in managing projects. It aids in planning, coordinating and tracking the progress, providing an effective way to understand and communicate your project’s timeline and dependencies.