A Tree Diagram is used to break a project down into increasing levels of detailed actions that must be carried out to complete the project. Your final list of actions can then be input to an Activity Network Diagram to schedule the project.
Some of the improvement projects that we take on are more complicated than others and some are very complex indeed. Some involve many people and many tasks that need to be identified, planned, scheduled, and coordinated. Do you sometimes find yourself in the daunting position of not really knowing where to start with a project? If so, a Tree Diagram will come to your rescue. This technique is a simple yet highly effective way of taking a large, complex project and breaking it down into the main stages that have to be covered. It then takes each of these project stages and breaks them down into the specific tasks that need to be carried out to successfully complete the project. It helps you to make sense of what would otherwise be a confusing and seemingly unmanageable 'fog'.
A Tree Diagram is much easier to do if you first use an Affinity Diagram to brainstorm for all of the tasks necessary to complete the project.
How to do it
1. Agree an objective to be achieved.
2. Use an Affinity Diagram to deduce the high level means of achieving the objective.
3. Break each of the high level means down into sub-means (your Affinity Diagram may have also produced these).
4. Use 'Post-Its'.
5. Break the sub-means down into specific actions.
6. Confirm that your final list of actions consists of everything you need to accomplish the objective.
Example
Say you had gained approval to replace a machine with a more modern and efficient one. Your Tree Diagram could look something like this:
