Affinity Diagram / KJ Analysis


An Affinity Diagram is an analytical tool used to organize many ideas into subgroups with common themes or common relationships. The method is reported to have been developed by Jiro Kawakita and so is sometimes referred to as the K-J method. The tool is commonly used within project management and allows large numbers of ideas stemming from brainstorming to be sorted into groups, based on their natural relationships, for review and analysis.

The affinity diagram organizes ideas with following steps:

  1. Write down the problem and record each idea on cards or notes.
  2. Look for ideas that seem to be related and put them into homogenous groupings.
  3. Sort cards into groups until all cards have been used.
  4. Put the groupings in the order of process.

Once the cards have been sorted into groups the team may sort large clusters into subgroups for easier management and analysis. Once completed, the affinity diagram is now created and can now be used for further analysis and improvements.