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Case Study #192 — 309 Software Failure Events Timeline

Southwest Airlines December 2022 holiday meltdown

Southwest Airlines cancelled more than 16,700 flights over about ten days during the year-end holidays, stranding hundreds of thousands of passengers and prompting a US Department of Transportation investigation and a $140 million fine.

2022-12
When it happened
Aviation
Sector
#192 of 309
Ranked by documented impact
01 — What Happened

The damage was public. The root cause was preventable.

Southwest Airlines cancelled more than 16,700 flights over about ten days during the year-end holidays, stranding hundreds of thousands of passengers and prompting a US Department of Transportation investigation and a $140 million fine.

Aviation
Sector affected
2022-12
Date of the event
#192
Rank in the 309 Software Failure Events Timeline
1
Distinct root-cause clause identified below
02 — The Root Cause

What the software actually got wrong

A winter storm disrupted the initial flight schedule, but Southwest's decades-old crew-scheduling software could not efficiently re-match tens of thousands of displaced crews to aircraft, unlike rivals with more modern systems, causing the disruption to snowball into a prolonged, company-wide collapse.

01Root Cause

A winter storm disrupted the initial flight schedule, but...

What Happened

A winter storm disrupted the initial flight schedule, but Southwest's decades-old crew-scheduling software could not efficiently re-match tens of thousands of displaced crews to aircraft, unlike rivals with more modern systems, causing the disruption to snowball into a prolonged, company-wide collapse.

How Requs AI Catches This

Requs AI Edge Case flags this exact pattern at the requirements and architecture stage — before a single line of code implementing it exists — so the assumption behind it gets challenged while it is still cheap to fix.

03 — How This Gets Caught Before It Happens

Beyond code coverage and "shall" testing

Root causes like this one rarely show up in code coverage or requirements-compliance testing, because nobody wrote a requirement anticipating the specific edge case that broke. Requs AI Edge Case and Requs AI Software FMEA are built to surface exactly this class of overlooked failure mode — before the software is written.

Requs AI Edge Case

Surfaces this before code exists

Identifies edge cases like this one at requirements and architecture time, using the Common Defect Enumeration to catalog failure patterns seen across hundreds of real-world software failures — including this one.

Requs AI Software FMEA

Connects the failure mode to the hazard

Traces this class of root cause directly to the system-level hazard it can produce, so a defect pattern like this one gets flagged during design review instead of after it ships.

Find the overlooked root causes before they ship.

Schedule a demonstration, or explore how Requs AI Edge Case and Software FMEA use the Common Defect Enumeration.