The big idea
🔍
Treat a symptom and it comes back
Everyone has watched an organisation fix the same thing four times.
Problem Solving & Decision Making · Lesson 3
Root Cause Analysis
beginner⏱ 17 min · 7 cards
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Symptom or Cause?
“The figures in the report were wrong.”
The weekly report went out with wrong figures. What is each of these?
The test is not "does this explain it?" but "if removed, does it stop coming back?"
Sort candidate explanations by what would actually stop recurrence.
The original example
Why did the machine stop?
The fuse tripped. Why? The bearing was under-lubricated. Why? The pump was not delivering. Why? The shaft was worn. Why? No filter, so filings got in.
Stop at the fuse and you replace fuses forever. Reach the filter and it stops — on every machine lacking one.
Key term
The answer that ends analysis
Is "human error" a root cause?
tap to reveal ↻
Almost never
It is where analysis stops when someone wants an ending. Keep going: why was the error possible, why was it not caught, why did the system let it cause harm?
Nuance
Careful
Common misconception
The Five Whys produces one chain. Real failures branch — go deep with it, then widen with a fishbone or you will miss parallel causes.
Quick check
What three components make something a problem?
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