1. What is Failure Rate?

Failure Rate (FR) is a reliability metric that measures the frequency at which failures occur over a specified period of time. It represents the number of failures per unit time and is commonly expressed as failures per hour.

2. How Does the Calculator Work?

The calculator uses the Failure Rate formula:

Where:

• \( FR \) — Failure Rate (per hour)
• \( Failures \) — Total number of failures (count)
• \( Total\ Time \) — Total exposure time (hours)

Explanation: The formula calculates the average failure frequency by dividing the total number of failures by the total operating time.

3. Importance of Failure Rate Calculation

Details: Failure rate calculation is essential for reliability engineering, maintenance planning, quality control, and risk assessment. It helps organizations predict system performance and plan preventive maintenance schedules.

4. Using the Calculator

Tips: Enter the total number of failures and the total operating time in hours. Both values must be valid (failures ≥ 0, total time > 0).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between failure rate and reliability?
A: Failure rate measures how often failures occur, while reliability measures the probability that a system will function without failure for a specified period.

Q2: What are typical failure rate units?
A: Failure rate is typically expressed as failures per hour (FPH), failures per million hours (FPMH), or failures in time (FIT) where 1 FIT = 1 failure per billion hours.

Q3: When is failure rate calculation most useful?
A: It's most useful during the useful life period of a product when failure rates are relatively constant (exponential distribution).

Q4: Are there limitations to failure rate calculation?
A: Yes, it assumes constant failure rate over time and may not accurately represent systems with wear-out or infant mortality failure patterns.

Q5: How is failure rate related to MTBF?
A: Failure rate (λ) is the reciprocal of Mean Time Between Failures (MTBF): λ = 1/MTBF for systems with constant failure rates.