A work breakdown is a deliverable-oriented breakdown of a project into smaller components, called tasks. This breakdown splits the project work into manageable steps that can be tackled by different people. Tasks are often dependent on the results of previous tasks. This sorting of work is not a strict requirement, but is most easily implemented by numbering tasks.
The work breakdown can be organized by grouping tasks under a container called a subprocess. This grouping helps the project team keep track of the status and progress of multiple tasks of the project.
Example of a work breakdown: Aircraft system design
In the figure below, a very simple example of an aircraft system design is presented in a work breakdown tree structure. As shown in the figure, on the last level of any tree branch there are only tasks. This means that any subprocess contains at least one task, as the only role of the subprocesses is to structure the project.
What is the role of tasks?
The tasks is where the product and work breakdown interact. Make sure to read this page as well.
Example of a work breakdown: Bike design
In the picture below, an example of a work breakdown structure inside KE-chain is shown.