The Ishikawa Diagram
Also known as the Cause-and-Effect Diagram or the Fishbone Diagram, this tool helps visualize the key characteristics and underlying causes of a problem.
The diagram begins with a clearly defined problem statement, represented at the “head” of the fish.
From it extends a horizontal “spine”, symbolizing the main issue.
Attached to this spine are major branches — the primary categories or factors contributing to the problem.
Each of these branches splits further into smaller bones — the specific causes that form each factor. Typically, several causes feed into each category.
This method helps you:
- See the interconnections among the factors contributing to a problem.
- Identify the root causes rather than symptoms.
- Choose the most effective corrective actions or solutions.
💡 The Ishikawa Diagram turns complexity into clarity — helping you see not just what happened, but why.
The Risk Map
Another powerful decision-making tool is the Risk Map, described in the book “Smart Choices” by John Hammond, Ralph Keeney, and Howard Raiffa.
It helps decision-makers evaluate uncertainty and potential outcomes to achieve the best possible result among alternatives.
How to Build a Risk Map
- Identify Your Key Doubts
Write down your main uncertainties for each decision option. Then assess their criticality — which doubts carry the highest stakes?
- Determine Possible Consequences
For every doubt, list the potential outcomes. The number of consequences should correspond to the number of identified risks.
- Define Probable Scenarios
Estimate the likelihood of each scenario. Understanding probabilities helps you judge how realistic each option is.
- Analyze the Results
Describe each outcome in detail — both qualitatively (“normal,” “poor,” etc.) and quantitatively (“within budget,” “too costly,” etc.).
For particularly complex decisions, go beyond listing risks — use a Decision Tree.
It helps visualize the chain of choices, showing how each option connects to its potential risks, probabilities, and outcomes.
💡 The Risk Map doesn’t eliminate uncertainty — it helps you navigate it intelligently.