What is an affinity diagram?
An affinity diagram brings order to a long, messy list of ideas. Instead of forcing ideas into categories decided in advance, the team groups ideas that "feel" related and then names each group. The method was developed by the Japanese anthropologist Jiro Kawakita to make sense of field notes, and it is the first of the seven management and planning tools. It works well with sticky notes on a wall, and just as well with a remote team on a shared screen.
How to make an affinity diagram
- State the question clearly, e.g. "What gets in the way of closing CAPAs on time?"
- Generate ideas: one idea per note, written as a short phrase with a verb and a noun.
- Sort silently: move notes into groups; anyone may move any note.
- Discuss: split large groups, merge similar ones, park outliers.
- Write headers that capture the theme of each group.
- Draw conclusions: which themes matter most and what to do about them.
Affinity diagram example
A quality team brainstorms why CAPAs close late and gets fourteen ideas. Grouped, they fall into four themes: not enough time or people, slow approvals, weak investigations, and information that is hard to find. Two ideas, ownership of supplier CAPAs and outdated root cause training, do not fit yet and stay ungrouped for discussion. The themes show that the problem is not just "people are busy": three of the four groups are about the process and the system.
What to do next
- Find how the themes drive each other with an interrelationship diagram.
- Choose which themes to work on with multivoting or an impact/effort matrix.
- Break the chosen theme down into actions with a tree diagram.
How to use this Affinity Diagram tool
- Write the question. Click the dark header and write the question or topic the ideas answer.
- Add the ideas. Paste a list of ideas (one per line) or click + to add sticky notes. One idea per note.
- Group them. Drag notes into columns of related ideas. Add groups with + and leave ideas that do not fit in "Not yet grouped".
- Name the groups. Click each header and write a short phrase that captures the common theme.
- Review together. Discuss the groups, split or merge them, and agree on the result.
- Export. Export the affinity diagram to PNG or PDF, or the grouped list to Excel.
Frequently asked questions
What is an affinity diagram?
An affinity diagram organizes a large number of ideas, issues or observations into natural groups based on their relationships, then names each group with a header. It is one of the seven management and planning tools and is also known as the KJ method, after Jiro Kawakita, who developed it in the 1960s.
When should I use an affinity diagram?
After a brainstorm, survey, interviews or a voice-of-the-customer exercise produces many ideas that need structure; when a problem is complex or unfamiliar; and when the team needs to build consensus. It is often the first step before an interrelationship diagram or a tree diagram.
How do you create an affinity diagram?
1 Write the question. 2 Write each idea on its own note. 3 Silently sort the notes into groups that feel related, moving notes freely. 4 Discuss, split or merge groups, and park ideas that do not fit. 5 Write a header for each group that captures the common theme. 6 Optionally arrange the groups into higher-level super-groups.
Why sort the notes in silence?
Silent sorting stops discussions from being dominated by the loudest voice or by premature labels. People react to the ideas themselves; patterns emerge from the data rather than from categories decided in advance.
What makes a good header?
A header should capture the essence of the group in a short phrase that someone who has not seen the notes would understand: "Approvals take too long" rather than "Process". Write headers after grouping, not before.
What is the difference between an affinity diagram and a fishbone diagram?
An affinity diagram builds categories bottom-up from the ideas themselves. A fishbone diagram uses predefined categories (such as the 6Ms) to organize possible causes of a specific problem. Use an affinity diagram when you do not know the categories yet.