Microsoft Azure Active Directory global outage
Microsoft 365 and Azure AD sign-ins failed for many customers worldwide for several hours, blocking access to Teams, Outlook, and other services.
The damage was public. The root cause was preventable.
Microsoft 365 and Azure AD sign-ins failed for many customers worldwide for several hours, blocking access to Teams, Outlook, and other services.
What the software actually got wrong
A backend service responsible for processing authentication tokens hit an unexpected condition that caused elevated latency and failures in validating sign-in requests.
A backend service responsible for processing authentication tokens hit...
A backend service responsible for processing authentication tokens hit an unexpected condition that caused elevated latency and failures in validating sign-in requests.
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.
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.
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.
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.