Example: who caused the outage?
A worked example, written to show the method.
Assumption I am questioning: The operator is the root cause.
Claim: Human error caused the outage.
This is a teaching example written by Varma. It is not a real incident.
An operator restarted the wrong service during a change window. The service stayed down for 40 minutes. The review says human error.
The post names a claim and an assumption. The replies ask why, check the facts and test what breaks.
The ladder
- assumption 0
- why 1
- rebuild 0
- breaks 1
- evidence 1
- note 0
3 replies
Why did the operator restart the live service and not the test copy?
The screen showed two buttons labelled Restart. They sat side by side. One hit the test copy and one hit production. Neither asked for confirmation.
The claim breaks here. Two destructive buttons had the same label and no confirmation. Any operator could slip. Fix the screen.