Mean Time To Failure (MTTF)

Security+ 🏆 • Security Operations 🛡️ • Difficulty: premium

Definition

Mean Time To Failure is a reliability metric that estimates the average operating time before a non-repairable component or system fails. It is used to understand expected lifespan, support replacement planning, and improve availability and resilience decisions.

Examples

  • A storage team reviews the MTTF of solid-state drives when selecting hardware for critical systems.
  • An organization uses MTTF estimates to plan when aging power supplies should be replaced before they fail.

Discover 🔎

Security is not only about stopping attacks. It is also about keeping important systems working. If a component fails unexpectedly, the business can still suffer downtime, lost access, or service disruption. Mean Time To Failure helps teams think about that risk by estimating how long a component is likely to operate before it fails.

This matters because availability is one of the core security goals. A highly secure service that fails often is still a weak service from a business point of view.

Remember: MTTF is about expected operating life before failure. It is usually used for things that are replaced, not repaired and returned to service.
Open the interactive lesson Browse more topics

Tip: The interactive version includes progress tracking, decks, and premium deep dives.