Chapter 2 – Testing Throughout the SDLC
Reliability Testing – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
Testing to determine the reliability of a software product under specified conditions for a specified period of time.
In simple words
Check the system keeps working correctly over time under expected load.
Exam tip
Reliability is a non-functional quality characteristic in ISO 25010.
Related terms
- Non-Functional TestingHow fast, how secure, how usable, how reliable — the ‘qualities’ around the feature, not the feature itself.
- Recoverability TestingHow well the system restores itself and its data after a failure.
- Stability TestingRun the system for a long time under normal load and watch for degradation.
Practice this term in the ISTQB Mock Test
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