Hierarchy diagram

Skill level: Basic


A hierarchy diagram (also called a tree diagram) classifies information by starting with broad categories and narrowing down to more detailed levels.

The hierarchy can be presented in a vertical or horizontal format and can include multiple levels of information as needed. A common use of the vertical format is an organization chart.


  • Process causes the team to think in increasing levels of detail, moving from general to specific
  • A useful way to organize information collected through brainstorming activities, such as after the use of an affinity diagram
  • Provides a visual representation of the various levels of detail, making it easier for others to understand the big picture and the details

How to Use

  • Step 1.  Capture the objective or intent of the diagram, usually at the top of a vertical tree or to the left of a horizontal tree.
  • Step 2.  Brainstorm and capture as many ideas as possible.
  • Step 3.  Place the captured ideas into logical groupings. An affinity diagram is a good way to do this.
  • Step 4.  Decide if the information looks complete or if something might be missing.
  • Step 5.  Capture any additional information from step 4 and place it under the appropriate groupings.
  • Step 6.  Repeat steps 4 and 5 until the hierarchy has enough detail to achieve your objectives.  For the final level of the diagram, focus on items that are either actions or goals.

Relevant Definitions

Affinity diagram/process: A tool that organizes large amounts of data into related categories based on their natural relationships. Typically used after a brainstorming exercise as a way to organize the ideas that the team generated.


The Generic Sales Company is getting ready to implement a new order taking system. The project team responsible for design, development, and delivery of the new system has just finished brainstorming a list of ideas related to implementation of the system:

  • Need to communicate the change to users
  • Training for users
  • Support people need training
  • What about a user manual?
  • Publish a newsletter article
  • (…and so on)

Once they complete their brainstorming, the group creates an affinity diagram and agrees that the main categories of ideas are communication, training, and documentation. They use these three main groupings to start the hierarchy diagram shown below. Within each of the three categories, they list the ideas they had captured during brainstorming and begin to add an additional level of detail, starting with meetings. Not yet shown, their final steps will be to capture specific actions and goals for the lowest level of detail.



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