Annualized Failure Rate Calculator
What is Annualized Failure Rate?
The Annualized Failure Rate (AFR) is a metric used to quantify the probability of a system, component, or piece of equipment failing within a one-year period. It's particularly useful in reliability engineering, manufacturing, and IT operations to assess and compare the failure performance of different products or systems over a standardized timeframe. A lower AFR generally indicates higher reliability.
How to Calculate Annualized Failure Rate
The AFR is calculated by first determining the raw failure rate over a given observation period and then scaling that rate to a one-year period.
The formula is:
Raw Failure Rate = (Number of Failures) / (Total Observation Period in Hours)
To annualize this rate, we assume a standard year consists of 8760 hours (24 hours/day * 365 days/year).
Annualized Failure Rate (AFR) = (Raw Failure Rate) * (8760 Hours / Observation Period in Hours)
Or, more directly:
AFR = (Number of Failures * 8760) / Total Observation Period in Hours
Interpreting the Result
The resulting AFR is typically expressed as failures per year. For example, an AFR of 0.05 means that, on average, 5 failures are expected per 100 units observed over a year, or 5% of the observed units are expected to fail annually.
Example Calculation
Let's say you have observed 15 components over a total period of 150,000 hours, and during this time, 3 of those components failed.
- Number of Failures = 3
- Total Observation Period = 150,000 hours
Using the formula:
AFR = (3 failures * 8760 hours/year) / 150,000 hours
AFR = 26280 / 150,000
AFR = 0.1752 failures per year.
This means that, based on this observation, you would expect approximately 0.1752 failures per year for every unit observed under similar conditions.