reliabilitetsfunktion
The reliabilitetsfunktion, also known as the reliability function, denotes the probability that a component or system will function without failure up to a given time t. It is commonly written as S(t) and is defined in terms of the lifetime T of the item as S(t) = P(T > t). Equivalently, if F(t) = P(T ≤ t) is the cumulative distribution function of the lifetime, then S(t) = 1 − F(t).
The function S(t) is nonincreasing, with S(0) representing the probability of surviving from time zero, typically
Reliability theory links S(t) to other common functions in survival analysis. The density f(t) = dF/dt satisfies
Estimation and application are central to reliability analysis. Nonparametric methods such as the Kaplan–Meier estimator estimate