- Censorship : Observation of a product that had not failed by the end of the follow-up period. Must be included in the calculation.
- R(t) : probability of still being operational at time t.
- MTTF : Mean Time to Failure. Not to be confused with a guaranteed service life.
- Default Rate : the probability of failing in the next instant, given that one has held out until now.
- β (beta) : Weibull shape parameter. 1: worn.
- η (eta) : Weibull scale parameter, the time at which approximately 63 % of the population has failed.
- δ (delta) : position, the third parameter of the Weibull distribution; the time elapsed before any failure occurs.
- Nevada : Triangular table of returns by sales period. Diagonal = age; column = calendar.
- Kaplan-Meier : observed survival curve, without any assumption about the distribution.
- Acceleration factor : ratio of service life under normal conditions to service life under increased stress.
Appendix: Definitions
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