{"id":9118,"date":"2026-06-18T08:07:04","date_gmt":"2026-06-18T06:07:04","guid":{"rendered":"https:\/\/lorit-consultancy.com\/en\/?p=9118"},"modified":"2026-06-18T08:11:03","modified_gmt":"2026-06-18T06:11:03","slug":"why-failure-rates-tell-only-part-of-the-story","status":"publish","type":"post","link":"https:\/\/lorit-consultancy.com\/en\/2026\/06\/why-failure-rates-tell-only-part-of-the-story\/","title":{"rendered":"Stressed to the Max: Why Failure Rates Tell Only Part of the Story"},"content":{"rendered":"

Introduction to Stress Factors<\/span><\/span><\/h2>\n

As a consultancy working on a wide variety of safety and reliability projects, we spend a lot of our time looking at failure rates and failure probabilities. In the world of electronic hardware,<\/span><\/span> there are numerous excellent sources defining failure rates,<\/span><\/span> e.g. FIDES, 217Plus, IEC 61709,<\/span><\/span> and the now–<\/span><\/span>retired (or rather integrated into ISO 26262) IEC TR 62380. For software,<\/span><\/span> there are also sources that can be used to estimate reliability, although it is a difficult subject. R<\/span><\/span>egarding reliability, there are complex strategies in software reliability growth models that can be applied,<\/span><\/span> e.g. those described by Neufelder: How reliable is your software growth? \u00bb Lorit Consultancy<\/a><\/p>\n

However, an area that is often given less focus than it perhaps should is the impact of mechanical and environmental stress. In this blog,<\/span><\/span> we look at how these topics are handled in existing standards and how practical strategies can be used to include these topics in analyses.<\/p>\n

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Source: Adobe Stock<\/em><\/p>\n

Key <\/span><\/span>Reliability Factors<\/h2>\n

The typical stress sources that impact devices during normal operational use, as listed in FIDES 2022, are:<\/span><\/span><\/p>\n