Interrelationship Digraph

Interrelationship DigraphInterrelationship digraphs show cause-and-effect relationships, and help analyze the natural links between different aspects of a complex situation. An interrelationship digraph:

  • Encourages team members to think in multiple directions rather than linearly
  • Explores the cause and effect relationships among all the issues, including the most controversial
  • Allows key issues to emerge naturally rather than to be forced by a dominant or powerful team member
  • Systematically surfaces the basic assumptions and reasons for disagreements among team members
  • Allows a team to identify root cause(s) even when credible data does not exist

When to Use an Interrelationship Digraph

How to Construct an Interrelationship Digraph

1. Create a Problem Statement

  • If using an original statement, (not from a previous tool or discussion) create a complete sentence
  • Everyone needs to clearly understand and agree on the problem statement
  • Write or place the problem statement at the top of the workspace

Example: The Planning Workgroup does not have equal representation from all four sectors in which the Partnership for Better Health will work.

2. Brainstorm Ideas

  • Brainstorm ideas and write each one on a separate note card or piece of paper
  • If using with another tool (e.g., an affinity diagram or fishbone diagram), take ideas from the most detailed row or final branches. Use these ideas to brainstorm other ideas


  • Potential members don't have time
  • Lack of charter (that identifies roles/responsibilities, decision-making process, mission, etc.)
  • Do not know all of the experts in the community (Anoka County)
  • Inadequate information regarding the direction of the Partnership for Better Health and opportunities for participation
  • Lack of lead agency staff time to do recruitment
  • Inertia related to use of technology that could bring off-siters "in" (e.g., videoconferencing)
  • Potential members do not understand personal or organizational benefit of participating
  • Closed Planning Workgroup meeting

3. Determine Relationships Between Ideas

  • For each idea, ask, “Does this idea cause or influence any other idea?” Draw arrows from each idea to the ones it causes or influences. Repeat the question for every idea.
  • Draw only one-way relationship arrows in the direction of the stronger cause or influence.



IDView Larger: Anoka County Interrelationship Digraph

4. Analyze the Diagram

  • Count the arrows in and out for each idea. Write the counts at the bottom of each box. The ones with the most arrows are the key ideas.
  • Note which ideas have primarily outgoing (from) arrows. These are basic causes or drivers.
  • Note which ideas have primarily incoming (to) arrows. These are final effects that also may be critical to address.
  • Be sure to check whether ideas with fewer arrows also are key ideas. The number of arrows is only an indicator, not an absolute rule. Draw bold lines around the key ideas.

5. Next Steps

  • Use common sense when you select the most critical issues to focus on. Issues with very close tallies must be reviewed carefully but in the end, it is a judgment call, not science.

Further Reading

More Information

Icon American Society for Quality: Relations Diagram
Icon The Coach's Guide to the Memory Jogger:
Interrelationship Digraph (PDF: 174KB / 12 pages)


Icon Tague: The Quality Toolbox
Icon Public Health Memory Jogger
If you belong to a local health agency in Minnesota and would like a Memory Jogger free of charge, please contact the QI Unit.