Monday, June 9, 2025
Use the Fishbone Diagram and 5 Whys to strengthen complaint handling
If the same issues keep resurfacing, there’s a deeper cause that’s being overlooked. And more often than not, it’s not what you think. It’s easy to assume you need more staff, but if good people keep leaving, the issue probably isn’t the role; it’s the process breaking down.
Fixing complaints sustainably means finding and addressing the real causes, not just the visible symptoms.
And to do that, you need time out of the trench and the right tools.
Here’s one combination that helped me more than once shift from chaotic working to one of clarity:
The Fishbone Diagram, and the 5 Whys analysis.
What is the purpose of a Fishbone Diagram?
Also known as the Ishikawa Diagram, the Fishbone is a visual cause-and-effect problem-solving tool. It helps teams identify root causes by organising contributing factors into structured categories.
It’s a great way to:
Cut through the noise to find the real problem
Encourages critical thinking
Brings different perspectives together
Helps teams ask better questions
What does a Fishbone Diagram help you identify?
During the Analyse, phase of improvement work (e.g. DMAIC: Define, Measure, Analyse, Improve, Control), a Fishbone diagram helps you:
Break down complex issues into manageable parts
Explore contributing factors
Moves you beyond assumptions to find root causes and supporting data
I've handed the fishbone template to the complaint teams and asked them to complete it, usually over a 48–72-hour period, and while handling live cases. There’s nothing like a real-life problem to trigger the mind!
🐡 When to use a Fishbone Diagram in complaint handling
When the same issue keeps resurfacing (e.g. missed SLAs)
When resolution happens, but complaints aren’t closed out (e.g. FOS escalations)
When there’s disagreement in the team about what’s going wrong
When you need to show others what’s behind recurring issues
Example: Poor service levels
Let’s say service levels are dropping. You can use a Fishbone to map potential causes under these six complaint-handling categories:
People – high turnover, low morale, inconsistent decisions
Processes & Policies – no escalation path, unclear ownership
Technology – manual logging, siloed tools
Customer Expectations – slow updates, lack of empathy
Regulatory Compliance – missing audit trails, poor documentation
Measurement & Feedback – no trend tracking, weak data loops from different sources
Once you’ve built your Fishbone Diagram, you can apply the 5 Whys…
What is the 5 Whys root cause analysis?
The 5 Whys is a simple questioning technique that helps you dig deeper by repeatedly asking:“Why is this happening?”
You ask “why?” for each symptom until you reach the root cause, often in five steps or fewer.
🧪 How the Fishbone Diagram and 5 Whys work together
Let’s continue the example:
Problem: Poor service levels
Why are service levels poor? → Complaints take too long to resolve
Why? → Cases are stuck waiting for approvals
Why? → Too many cases for the Team Leaders to review
Why? → No clear escalation process
Why? → No prioritisation policy in place
Root cause: Lack of structured escalation and prioritisation.
💡Tip: Split the team into two or three sub-teams and issue each with a Fishbone Diagram and let it sit with them for a day or two. Then ask them to each apply the 5 Whys to their diagrams and see what you get.
What are the 6 elements of a Fishbone Diagram?
Adapted for regulated complaints handling, we recommend these six categories:
People
Process & policy
Technology
Customer expectations
Regulatory compliance
Measurement & feedback
What are the 7 traditional categories?
The original Ishikawa model uses:
People
Policies
Procedures
Placement
Product
Promotion
Processes
Price
You don’t need to use all eight; adapt what makes sense for your complaint or use case.
This tool is widely adopted across regulated sectors like healthcare, financial services, and customer service, for example, the NHS also recommends Fishbone diagrams as part of root cause analysis.
🛠️ 5 steps for creating a Fishbone Diagram
Write the problem statement clearly at the 'head' of the fish
Draw the main 'bones' (categories) off the spine
Brainstorm causes within each category
Ask 'why?' repeatedly to go deeper
Highlight potential root causes for further analysis or action
Why use the Fishbone with the 5 Whys?
The Fishbone helps you look wide. The 5 Whys helps you look deep, and together:
You map causes clearly and concisely
Then dig into what's really driving the problem
Without relying on guesses and assumptions*
Advantages of the Fishbone Diagram
Easy to understand and explain
Useful when time is limited or resources are scarce
Helps simplify complex issues
Great for team collaboration and root cause sessions
Sparks ideas even when you’re not sure where to start
Provides a visual map you can return to
Visuals help stakeholders remember your message
Disavantages of the Fishbone Diagram
Can get too broad or messy if not focused on the problem
* May rely too heavily on opinions if not supported by data
Doesn’t prioritise causes, it just maps them
Can lead to false leads if the categories aren’t well chosen
💡 Tip: Always bring in complaint data and team insight to balance out the diagram.
How to create a Fishbone Diagram in Word
Open a blank document
Use Insert > Shapes to draw a horizontal arrow
Add text boxes branching off the spine
Label with your chosen categories
Add contributing causes under each
Complaint management toolbox
Fixing complaints starts with understanding what’s broken, not just what’s visible.
This is one small tool that can help you get there faster, and with the whole team aligned, you may also find our blog describing The 5 Cs of complaint handling and how to use the framework effectively useful.
Over the next few weeks, we’ll be sharing more tools to try and help you. If you’d like to share things that have worked for you, please get in touch.