Weibull Reliability Calculator
Compute component reliability and expected MTTF using the two-parameter Weibull distribution with characteristic life η and shape parameter β.
How to Use the Weibull Reliability Calculator
- Enter the characteristic life η in hours.
- Enter the Weibull shape parameter β from your fit.
- Enter the mission time t.
- Click Calculate.
使用场景
- •Component qualification reports.
- •Warranty and spare-part planning.
- •Teaching reliability engineering.
公式
R(t) = exp(−(t/η)^β). MTTF = η · Γ(1 + 1/β) ≈ η · β^(−1/β).
常见问题
How do I interpret β?
β < 1 indicates early-life (infant-mortality) failures, β = 1 means constant hazard (exponential distribution), and β > 1 corresponds to wear-out failures.
What is η?
η is the characteristic life at which 63.2% of the population has failed, regardless of β. It has units of time (hours).
How good is the MTTF approximation?
β^(−1/β) is within ~5% of the exact Γ(1+1/β) for β between 0.5 and 4. For β ≈ 1, MTTF ≈ η; for β = 3.44 (normal-like), MTTF ≈ 0.9 η.