Creating a fishbone diagram (also known as an Ishikawa diagram or cause-and-effect diagram) is a structured way to brainstorm potential causes of a specific problem. Here's a step-by-step guide:
1. Define the Problem (Effect)
- State the problem clearly and concisely. This is the "effect" you are trying to analyze. Be specific! For example, instead of "Low Sales," use "15% Decrease in Q3 Sales of Product X."
- Write the problem statement in a box (the "head" of the fishbone) on the right side of your paper or digital whiteboard.
- Draw a horizontal line (the "spine") extending to the left of the box.
2. Identify Main Categories of Causes
- Brainstorm the major categories of potential causes. Common categories include:
- The 6 Ms (Manufacturing): Machine, Method, Material, Manpower, Measurement, and Mother Nature (Environment).
- The 8 Ps (Marketing): Product, Price, Place, Promotion, People, Process, Physical Evidence, and Productivity & Quality.
- The 4 Ss (Service): Surroundings, Suppliers, Systems, Skills.
- Customize these categories to fit your specific situation. You might use "Equipment," "Process," "People," and "Materials," for instance.
- Draw diagonal "bones" branching off the spine for each category. Label each bone with its category name.
3. Brainstorm Possible Causes for Each Category
- For each category, brainstorm all possible causes that could contribute to the problem. Ask "Why?" repeatedly to drill down to the root causes. For example, if "Machine" is a category, ask "Why might the machine be causing the problem?" This could lead to answers like "Incorrect Calibration," "Worn Parts," or "Inadequate Maintenance."
- Write these potential causes as smaller branches off of the main category bones. Continue branching out with sub-causes if necessary.
4. Analyze and Refine the Diagram
- Review the diagram for completeness and accuracy. Are there any missing categories or causes? Are any causes listed in the wrong category?
- Look for causes that appear in multiple categories. These may be critical root causes that need further investigation.
- Prioritize the causes based on their potential impact and likelihood. Methods like Pareto analysis can be helpful here.
5. Develop Action Items
- For each prioritized cause, develop specific action items to investigate and address it. This might involve data collection, process changes, training, or equipment repairs.
- Assign responsibility for each action item and set deadlines.
- Track progress on the action items and adjust your approach as needed.
Example
Imagine the problem is "High Customer Churn Rate." A simplified fishbone diagram might look like this:
- Head: High Customer Churn Rate
- Spine: Extends to the left.
- Bones:
- Product: (Causes: Poor Quality, Lack of Features, Doesn't Meet Needs)
- Customer Service: (Causes: Long Wait Times, Unhelpful Agents, Rude Staff)
- Pricing: (Causes: Too Expensive Compared to Competitors, Hidden Fees, Lack of Value)
- Marketing: (Causes: Misleading Ads, Unrealistic Expectations, Poor Targeting)
By systematically exploring potential causes in different categories, a fishbone diagram helps you identify the root causes of a problem and develop effective solutions.
