Catastrophic failures — such as a security breach or a complete outage leading to an unavailable product or service — are classified as Sev0 incidents. On a severity scale of 1–3, Sev0 is dire. It brings business to a complete standstill and may lead to loss of revenue and a damaged reputation. A Sev0 incident usually has no quick workaround; it requires a coordinated effort beyond the engineering team to diagnose, correct, and manage.

Imagine being one of the world’s largest banking institutions and experiencing a critical severity security incident that affects millions of customers and billions of dollars. Now imagine it takes 20 minutes from the first notification to log a response and track down all relevant information from a variety of global systems just to understand the context and nature of the incident.