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The Fishbone Technique

Also called Ishikawa or cause-and-effect diagrams. Maps all potential causes of a problem into categories, revealing the full landscape of contributing factors. Best for complex problems where multiple independent causes may be at play.

When to Use Fishbone vs 5 Whys

Use 5 Whys when you suspect a single causal chain—one thing led to another. Use Fishbone when the problem has many potential contributing factors across different domains (process, people, tools, environment). Fishbone maps breadth; 5 Whys maps depth. They can be combined—Fishbone to identify major cause categories, then 5 Whys on the most significant ones.

Standard Categories

The classic manufacturing categories (6 Ms) don't always fit. Choose categories that match the problem domain:

For technical/product problems:

  • Code/Architecture
  • Infrastructure/Tools
  • Process/Workflow
  • People/Skills
  • External Dependencies
  • Requirements/Specs

For business/operational problems:

  • People
  • Process
  • Technology
  • Policy
  • Environment
  • Communication

For service/customer problems:

  • Training
  • Tools/Systems
  • Process
  • Communication
  • Policy
  • External Factors

Don't force-fit categories. If a category has no relevant causes, drop it. If you need a category that doesn't exist, add it.

Facilitation Approach

Start with the problem statement as the "fish head." For each category, brainstorm potential causes without judging yet. Ask: "What in this category could contribute to this problem?" Probe with "What else?" until the category feels exhausted.

After mapping, identify the most likely primary causes. Mark them. These become candidates for deeper analysis (5 Whys) or immediate action.

Output Format

# Fishbone Analysis: [Problem Statement]

## Problem
[Clear statement of the effect being analyzed]

## Cause Categories

### [Category 1]
- [Potential cause]
- [Potential cause] ⭐ (likely primary)
- [Potential cause]

### [Category 2]
- [Potential cause]
- [Potential cause]

### [Category 3]
- [Potential cause] ⭐ (likely primary)
- [Potential cause]

[Continue for each relevant category]

## Primary Causes
The most likely contributors based on evidence and discussion:
1. **[Cause]** — [Why this is likely significant]
2. **[Cause]** — [Why this is likely significant]

## Recommended Next Steps
1. [Investigate or address primary cause 1]
2. [Investigate or address primary cause 2]

Visual Representation (Text)

For a visual summary, use ASCII:

                    ┌─ [Cause]
         [Category] ├─ [Cause] ⭐
                    └─ [Cause]
                              \
                    ┌─ [Cause]  \
         [Category] ├─ [Cause]   ====> [PROBLEM]
                    └─ [Cause]   /
                              /
                    ┌─ [Cause] ⭐
         [Category] └─ [Cause]

This visual is optional—the categorized list is the primary output.