Describe root cause analysis tool focusing on 5 why analysis method. Including sample, practice and common mistake & tips.

1. Root cause analysis (RCA)
5 Why method
KienDN, 2018-Oct-29
Daongockien.vn@gmail.com

2. CONFIDENTIAL
Agenda
• Overview
• 5 Why method
• Practice
• Common mistake & Tips
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3. CONFIDENTIAL
OVERVIEW
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4. CONFIDENTIAL
Overview
• Why root cause analysis?
• The problem is not problem. The problem is your attitude about the problem.
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5. CONFIDENTIAL
Overview
• Type of solution
– Mop-it (temporary)
• Treat it
• Tolerate it
• Redirect it
– Stop-it (permanent)
• Prevent it
• Eliminate it
• Reduce it
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6. CONFIDENTIAL
Overview
• Common known method
– Easy, simple
– Cause & Effect, complex
– Brainstorming, group
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7. CONFIDENTIAL
5 WHY METHOD
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8. CONFIDENTIAL
5 Why method
• Fundamental
• Template
• Process
• Sample
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9. CONFIDENTIAL
5 Why method
• Fundamental
– Origin: Toyota
– Why, not Who?
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– Multiple Why
– Multiple Root cause

10. CONFIDENTIAL
5 Why method
• Template
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11. CONFIDENTIAL
5 Why method
• Process
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1.Select problem
2.Define problem (be specific, small,
realistic)
3.Ask why -> root cause -> problem
doesn’t happen again.
4. Implement countermeasures
(communicate the change with everyone)
5. Review, modify countermeasure
6. Update system procedure, training
7. Implement system, monitor

12. CONFIDENTIAL
5 Why method
• Sample
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John lost money in his bank account
linked to a credit card
Because someone used his credit
card to buy something on Amazon
Because John only checks bank’s
balance when he’s going to buy
something
Because his user, password was
stolen after he bought dress for his
girl friend on Amazon
Because he ever entered user name,
password to login Amazon at cafe
shop
Because John could not check bank
balance every day, only check when
having transaction or buy smt.
Because they could access to his
Amazon account.
Because cafe shop provides free Wifi
and someone could capture data
going in-out that wifi.
John don’t know there was some
irregular transactions.
Because someone be able to access
to his account using other device
and bought something
Because nothing notice him so that
he could stop bank account right
after the first irregular transaction
Because his smartphone was out of
3G/4G network capacity that day
Because John don’t limit and don’t
know other devices was accessing to
his account
Because he didn’t register
something that notify him
immediately
Because he didn’t register monthly
3G/4G service.
Because trusted devices option is
not turn ON.
Turn ON trusted devices security
option
Register SMS notification
- Don’t use public café wifi for
money related stuff.
- Register monthly 3G/4G service
Why?
Why?
Why?
Action
Root cause
Why?
Because he saved credit card
information permanently on
Amazon
Delete permanent credit card
information on Amazon. Only input
temporally when requested.

13. CONFIDENTIAL
PRACTICE
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14. CONFIDENTIAL
Practice
1. Problem 1: Kent is get dumped
by his girlfriend, Jenny, after 3
years dating.
2. Problem 2: There was a serious
bug detected when user
purchase over 100 goods on our
released system.
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15. CONFIDENTIAL
COMMON MISTAKE & TIPS
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16. CONFIDENTIAL
Common mistake & Tips
• COMMON MISTAKE
– Not right problem statement
– Not the right person or one man
show
– Know the root cause at first time
– Blame to who, someone else or
human error
– Try to fix others than problem in
your circle influence
– Think more procedures solve
problem
– Select lack of training, leadership or
management support, or funding
to be root causes. No, it’s solution.
– Not confirming countermeasure
really led to improvement
• TIPS
– Go to gemba, also ask members
not only manager
– Root cause often relates to
organization issue or process issue
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17. CONFIDENTIAL
Thank you!
Q&A
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