What is an Affinity Diagram

Guide: Affinity Diagrams

An affinity diagram, developed in the 1960s by Kawakita Jiro and often referred to as the KJ method, is a powerful visual tool for organizing complex data into meaningful categories. It excels in situations where traditional methods of data analysis and organization might be inadequate, especially with voluminous or intricate information.

The process involves collecting diverse data points, such as ideas, observations, or research findings, and systematically grouping them based on inherent relationships. This technique is particularly effective in unveiling hidden patterns and connections, facilitating a deeper comprehension of the subject matter, and is applicable in various scenarios including brainstorming sessions, problem-solving, data analysis, and project management.

Table of Contents

An affinity diagram is a visual tool designed to help groups or individuals organize large amounts of data into meaningful categories. The Affinity diagram was developed in the 1960s by Kawakita Jiro and is often referred to as the KJ method. The strength of an affinity diagram lies in its ability to simplify and clarify complex sets of information, making it an invaluable tool in various professional and academic fields.

The process begins with a collection of data points—these could be ideas, observations, research findings, or any other form of information. These data points are then systematically grouped based on their intrinsic relationships. The goal is to uncover patterns and links that aren’t immediately evident, allowing for a deeper understanding of the subject matter.

Affinity diagrams are particularly beneficial when the data to be analyzed is voluminous or complex, where traditional methods of organization and analysis might fall short. They provide a structured yet flexible framework for synthesizing and interpreting large datasets.

Example of an affinity diagram with quality and cost

Example of an affinity diagram with quality and cost

Why use Affinity Diagrams?

The main use of an Affinity Diagram is to combine and categorize data. This method is great for situations where there is lots of information and where the information may be overwhelming. For example, when faced with hundreds of customer feedback comments, an affinity diagram can help identify common themes and issues, which might be lost in the sheer volume of data.

One advantage of using the diagram is its ability to show relationships between seemingly different pieces of information. By ordering data into related groups (affinity), it becomes easier to identify themes, recognize patterns, and understand the broader categories that may not have been initially obvious.

The purpose of the affinity diagram is not just to organize data but to transform it into an understandable and actionable format. It’s a tool that helps to convert raw data into knowledge and provides a foundation for informed decision-making, problem-solving, or strategy development. 

When to Use an Affinity Diagram?

Affinity Diagrams are a fairly flexible tool and can easily be applied to a range of scenarios, such as:

Brainstorming sessions

They are particularly effective in brainstorming settings where a team generates a multitude of ideas. The diagram can be used to categorize these ideas, making it easier to focus on specific themes or issues.


When in a problem-solving session, the Affinity Diagram can be used to help break the problem down into smaller, more manageable parts. Using the method to sort different aspects of a problem, teams can develop a more complete understanding and more effective solutions.

Team Problem Solving

Data Analysis

The diagram is also useful in a situation involving data analysis. When you are dealing with qualitative data like customer feedback, interview transcripts, or observation studies, The diagram can be used to organize the data into logical categories for further analysis.

Project Management

In project management, affinity diagrams can be used to categorize tasks, risks, or project requirements. This categorization aids in creating a more structured approach to project planning and execution.

Step-by-Step Process to Using Affinity Diagrams

Step 1: Data Collection

The first step is to collect all relevant data, ideas, or information that needs organizing. This data could come from:

  • Brainstorming Sessions: Capture all the ideas generated during these sessions.
  • Customer Feedback: Collect comments, reviews, or survey responses.
  • Research Findings: Include observations, study results, or statistical data.
  • Organizational Data: This might include internal reports, process information, or historical data.

The objective is to have a comprehensive set of data that represents all angles of the topic of the problem you are exploring.

Step 2: Record Ideas

The next step is to record these ideas, if they are not already recorded. This is best done by writing each input down on a separate sticky note or card. Doing this allows you to have flexibility and easy movement of ideas during the categorization process, provides visibility for each idea or data point, and allows you to easily sort them into groups. Finally, you should ensure that each note is concise but clear enough to convey the idea or data point effectively.

Step 3: Set up a Working Space

To organize the ideas, you will need a large, clear surface, such as a wall, table, or even digital tools. Personally, we prefer to use a clear way as it allows for people to be involved and interact with ideas, as well as making it clear and easily visible to all involved. The space should be large enough to accommodate all the notes and allow for grouping and re-grouping.

Step 4: Organize

This can be done in two ways: either as a group or individually.

Individually, it would be done in silence, where each participant independently sorts the notes into groups based on their perceived natural relationships or similarities. The silent aspect is crucial because it prevents influence or dominance by more vocal participants, and each participant can form their own connections without external influence.

Whereas, if done as a group, this can be done through discussion of each idea and using the power of group thinking to agree on the affinity of ideas. Either way can work, and it is dependent on the group of people and the situation to judge which method is most suitable. 

Step 5: Discuss and Refine (depending on previous step)

If you do the silent grouping, then after this, team members come together to discuss the categories formed. During this phase:

  • Refine Groups: Move notes as needed, merge similar groups, or split larger ones into subcategories.
  • Encourage Discussion: Each member explains their rationale for the grouping, fostering a deeper understanding of different perspectives.

Step 6: Create and Label Categories

Once there is consensus on the groups, create clear and concise labels for each category. These labels should reflect the core essence or theme of the ideas within the group. It’s important that the content decides the category title and not set the titles and make the content fit the title. These labels will also provide a quick understanding of what each group represents and make it easier to reference and discuss the groups moving forward.

Step 7: Draw Conclusions

The final step involves analyzing the organized data to gain insights. Look for what common themes have emerged.  Are there areas with little or no data? What do the groupings suggest in terms of decision-making, problem-solving, or strategy development?

This analysis can lead to actionable insights, guide future actions, or inform decision-makers.


The affinity diagram is a dynamic and flexible tool that transforms overwhelming data into structured, actionable insights. Through a meticulous process of data collection, recording, organizing, and analysis, it enables the identification of underlying themes and patterns in complex information sets.

This method is particularly useful in diverse settings, from brainstorming and problem-solving to project management and data analysis. By facilitating the categorization of ideas into coherent groups and encouraging comprehensive discussion and refinement, affinity diagrams serve as a foundation for informed decision-making and strategy development, making them an invaluable asset in both professional and academic spheres.


A: An affinity diagram is a visual tool used to organize and categorize a large number of ideas, opinions, or data into meaningful groups based on their natural relationships.

A: An affinity diagram is commonly used in brainstorming sessions, problem-solving exercises, project planning, and process improvement initiatives. It helps to identify common themes, prioritize ideas, and generate consensus among team members.

A: To create an affinity diagram, follow these steps:

  1. Write down individual ideas, opinions, or data on separate sticky notes.
  2. Arrange the sticky notes on a large surface, such as a wall or a whiteboard, allowing for free movement.
  3. Look for connections and similarities between the sticky notes and group them together accordingly.
  4. Create headings or labels for each group to represent the common theme.
  5. Review and refine the groupings until a meaningful and logical structure emerges.

A: Some benefits of using an affinity diagram include:

  • Organizing a large amount of information into manageable groups.
  • Facilitating team collaboration and encouraging participation.
  • Identifying common patterns and themes that may not be immediately apparent.
  • Promoting a structured approach to problem-solving and decision-making.
  • Creating a visual representation that aids in understanding and communication.

A: While affinity diagrams are commonly used in team settings, individuals can also utilize this technique. It can be a valuable tool for individuals to organize their thoughts and ideas, especially during personal reflection, planning, or decision-making processes.

A: Yes, some limitations and challenges of using an affinity diagram include:

  • The process can be time-consuming, especially with a large number of ideas or data points.
  • The interpretation and grouping of ideas may be subjective, leading to potential biases.
  • It may require a physical space or a virtual collaboration tool to accommodate the sticky notes.
  • Group dynamics and individual biases can influence the outcome of the diagram.
  • The diagram itself does not provide solutions but serves as a tool for organizing and analyzing information.

A: Yes, affinity diagrams can be adapted for virtual or remote collaboration. Online tools and software can be used to replicate the sticky note grouping process, allowing team members to contribute and organize ideas from different locations.

A: Affinity diagrams are also referred to as affinity charts, KJ Method (named after its creator Kawakita Jiro), or cluster analysis.

A: The affinity diagram was developed by Jiro Kawakita, a Japanese anthropologist and management consultant, in the 1960s as part of his research on quality management and organizational improvement methods.

A: Yes, some alternatives to the affinity diagram include mind mapping, concept mapping, fishbone diagrams (Ishikawa diagrams), and prioritization matrices. These tools serve similar purposes of organizing and analyzing information but may have different visual structures or approaches.


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Daniel Croft

Daniel Croft is a seasoned continuous improvement manager with a Black Belt in Lean Six Sigma. With over 10 years of real-world application experience across diverse sectors, Daniel has a passion for optimizing processes and fostering a culture of efficiency. He's not just a practitioner but also an avid learner, constantly seeking to expand his knowledge. Outside of his professional life, Daniel has a keen Investing, statistics and knowledge-sharing, which led him to create the website learnleansigma.com, a platform dedicated to Lean Six Sigma and process improvement insights.

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