Reliability

What does the failure-rate unit FIT mean?

  1. AOne failure per billion (10⁹) device-hours
  2. BOne failure per year
  3. COne failure per 10,000 hours
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Answer: A. One failure per billion (10⁹) device-hours

1 FIT is a failure rate of one failure per 10⁹ device-hours. For example, using one million parts rated at 100 FIT for 10,000 hours would be expected to produce 10⁶ × 10⁴ × 100 / 10⁹ = 1000 failures. It is a unit used to evaluate parts with low failure rates, such as semiconductors.

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