Problem Tree

Purpose

The Problem Tree (also called Issue Tree or Cause-Effect Tree) helps teams move beyond symptoms to root causes. By structuring a problem as a tree — trunk (core problem), roots (causes), and branches (effects) — the group sees the full causal chain and can target interventions at the roots rather than pruning branches that keep growing back.

At a glance

How to run

1. State the core problem (3 min): Write the problem on the trunk of a tree drawn on the board.
2. Map causes (10 min): Ask "Why does this problem exist?" Write each cause as a root. For each cause, ask "Why?" again to go deeper (sub-roots). Go 2–3 levels deep.
3. Map effects (8 min): Ask "What does this problem cause?" Write each effect as a branch. Go 1–2 levels up.
4. Verify the tree (5 min): Read the tree from bottom to top: "Because of [root], [problem] happens, which leads to [branch]." Does it make sense?
5. Prioritise roots (4 min): Which root causes are most addressable and impactful? Mark them for action.

Materials needed

• Large paper or whiteboard with a tree drawn (trunk, roots, branches)
• Sticky notes and markers
• Dot stickers for prioritisation

Pitfalls & common mistakes

• Confusing causes and effects: If "low morale" is both a cause and an effect, the tree has a loop — separate them carefully.
• Stopping at one level: One "Why" is not enough. Go at least two levels deep.
• Addressing branches instead of roots: The whole point is to fix causes, not effects.
• Too many roots: Focus on the 5–8 most significant causes.

Inclusion & accessibility

• Use silent brainstorming for causes and effects to include all voices.
• The visual metaphor is intuitive across cultures.
• Provide the tree template in advance for participants who need processing time.

Variations

• Solution Tree: After the Problem Tree, create a mirror tree where each root cause becomes a root solution.
• 5 Whys + Problem Tree: Combine the 5 Whys technique for deeper root exploration.
• Fishbone + Problem Tree: Use Ishikawa categories (People, Process, Technology, etc.) to structure roots.

When NOT to use this

• When the problem is already well-analysed and causes are known.
• When the problem is too broad — narrow the scope first.
• When the group needs solutions, not more analysis — the Problem Tree is diagnostic.

Source & further reading

• Logical Framework Approach (development sector)
• Overseas Development Institute (ODI): Problem Tree Analysis
• Gamestorming: Problem Tree