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Failure Rate Formula:
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Failure rate (λ) represents the frequency at which a component or system fails, while MTBF (Mean Time Between Failures) is the average time between failures of a repairable system. These metrics are fundamental in reliability engineering and maintenance planning.
The calculator uses the inverse relationship formula:
Where:
Explanation: The failure rate is mathematically the reciprocal of MTBF, representing the probability of failure per unit time for a system operating in its useful life period.
Details: Calculating failure rate is essential for reliability analysis, maintenance scheduling, spare parts planning, and system design optimization. It helps predict system performance and plan preventive maintenance activities.
Tips: Enter MTBF value in any consistent time units (hours, days, years, etc.). The calculator will return failure rate in failures per the same time unit. MTBF must be greater than zero.
Q1: What is the difference between MTBF and MTTF?
A: MTBF (Mean Time Between Failures) is for repairable systems, while MTTF (Mean Time To Failure) is for non-repairable systems. Both use the same failure rate calculation.
Q2: What are typical MTBF values?
A: MTBF values vary widely by industry - from thousands of hours for consumer electronics to millions of hours for high-reliability aerospace components.
Q3: Can failure rate change over time?
A: Yes, failure rates typically follow a "bathtub curve" with high initial failure rates, followed by a constant rate period, then increasing rates as components wear out.
Q4: How is reliability related to failure rate?
A: Reliability R(t) = e^(-λt), where λ is the failure rate and t is time. This exponential relationship assumes constant failure rate.
Q5: What are common units for failure rate?
A: Common units include failures per hour, failures per million hours (FPMH), or FIT (Failures In Time = failures per billion hours).