Step 1: Identify the “Head” (The Problem)

Every fish needs a head. Draw a box on the far right side of a large piece of paper or whiteboard. Inside, write down the specific problem you are facing.

• Tip: Be as specific as possible. Instead of “Low Sales,” try “20% drop in Q3 online checkout completions.”
• Draw a long horizontal arrow pointing to this box. This is the “spine” of your fish.

Step 2: Add the “Bones” (The Categories)

Now, draw diagonal lines (the ribs) coming off the spine. To keep your brainstorming organized, use the classic 6Ms of manufacturing or the 4Ps of service. Choose the set that fits your world:

The 6Ms (Production)	The 4Ps (Service/Office)
Manpower: People & skills	Policies: Rules or regulations
Methods: Processes & rules	Procedures: Steps in the task
Materials: Raw goods & data	People: Staff & customers
Machines: Tools & software	Plant: The environment/space
Measurement: Data & inspection
Mother Nature: Environment

Step 3: Brainstorm the Causes

Now, gather your team. For each category, ask: “Why is this happening?” As you identify potential causes, draw smaller horizontal lines off the category “ribs.” If a cause is complex, you can even draw sub-branches off those lines. Don’t filter ideas yet—just get them on the bone!

Step 4: The “5 Whys” Drill-Down

To find the root cause, don’t stop at the first answer. Pick a cause on your diagram and ask “Why?” again.

Example: > * Initial Cause: The machine stopped.

• Why? The fuse blew due to an overload.
• Why? The bearing wasn’t lubricated.
• Why? The pump isn’t circulating oil.
• Root Cause: The pump intake is clogged with metal shavings.

Step 5: Analyze and Take Action

Look at your completed fish. Are there certain causes that appear in multiple categories? Are there areas where the “bones” are very dense?

1. Circle the most likely root causes.
2. Verify them with real-world data.
3. Develop an action plan to address those specific points.