Toolkit · Root Cause
Five Whys Worksheet
A structured way to go beyond surface symptoms and uncover root causes—without pretending your guesses are facts.
- Separates facts from assumptions at every “why”.
- Prevents Five Whys from becoming five guesses in a trench coat.
- Ends with learnable next actions, not just a clever diagram.
- Works for product, ops, support, and strategy problems.
How to use this worksheet
The Five Whys only work when you separate what you know from what you're assuming.
- [K] = Known (we have data / evidence).
- [A] = Assumed (it seems logical, but unverified).
- [?] = Uncertain (worth investigating).
Without that discipline, the Five Whys become five guesses dressed up as insight. Use the tags on every answer.
Five Whys Worksheet
Below is the full worksheet in a readable format. Start with a clear problem, branch your whys, tag each answer as [K], [A], or [?], and finish with concrete questions, data, and experiments.
Important note on tags
The Five Whys only work when you're willing to separate what you know from what you're assuming. Every answer gets a tag:
- [K] = Known (we have data / evidence)
- [A] = Assumed (it seems logical but unverified)
- [?] = Uncertain (worth investigating)
Without that discipline, the Five Whys become five guesses dressed up as insight.
Starting Question
Write your initial problem statement:
Why is [PROBLEM] happening?
Example: Why are customers churning?
First Level: List All Possible Answers
Don't edit yourself. Write every answer you can think of, even ones that seem unlikely:
- 1. ________________________________________________ [ ] [K] [A] [?]
- 2. ________________________________________________ [ ] [K] [A] [?]
- 3. ________________________________________________ [ ] [K] [A] [?]
- 4. ________________________________________________ [ ] [K] [A] [?]
- 5. ________________________________________________ [ ] [K] [A] [?]
Mark each answer:
- • [K] = I know this is true (I have data / evidence)
- • [A] = I'm assuming this (it seems logical but unverified)
- • [?] = I'm uncertain (worth investigating)
Second Level: Pick One Path and Branch It
Choose one answer from above and ask why again. This time, write multiple possible reasons:
Why does [YOUR CHOSEN ANSWER] happen?
- Path A: ___________________________________ [ ] [K] [A] [?]
- Path B: ___________________________________ [ ] [K] [A] [?]
- Path C: ___________________________________ [ ] [K] [A] [?]
Third Level: Follow One Branch Deeper
Pick the path that seems most promising and ask why again:
Why does [CHOSEN PATH] happen?
Answer: _____________________________________
Mark: [ ] [K] [A] [?]
Fourth Level: Keep Going
Ask why again:
Why does [PREVIOUS ANSWER] happen?
Answer: _____________________________________
Mark: [ ] [K] [A] [?]
Fifth Level: Last Why
One more level:
Why does [PREVIOUS ANSWER] happen?
Answer: _____________________________________
Mark: [ ] [K] [A] [?]
What You Need to Learn
Look back at everything you marked [A] or [?]. For each one, write:
- What I assumed: _____________________________________
- How I could verify it: _____________________________________
- Who I need to ask: _____________________________________
Root Cause Check
Look at your final answer from the fifth level. Ask yourself:
Is this something we can:
- • Measure with data
- • Test with an experiment
- • Change directly
Or is it:
- • A blame statement (“customers don't understand X”)
- • Circular reasoning (leads back to the original problem)
- • Convenient (confirms what we already wanted to do)
If you checked any of the bottom three, go back and try a different branch.
Next Actions
Based on your analysis, what do you need to do next?
Questions to ask customers
- 1. ___________________
- 2. ___________________
Data to gather
- 1. ___________________
- 2. ___________________
Experiments to run
- 1. ___________________
- 2. ___________________