Glossary
Failures modelling of an active antenna and architecture modifications

reliability [ECSS-S-ST-00-01C]

Probability that a system will perform a required function, under certain conditions, for a certain period of time. This probability is a function of time and is denoted R(t).

Défaillance ; failure [ECSS-S-ST-00-01C]

Event leading to the end of an element's ability to perform a required function.

Failure rate [IEC 61131-6]

Reliability parameter λ(t) of an entity (components or simple systems) such that λ(t) · dt is the probability of failure of this entity between t and t + dt, provided no failure has occurred between instants 0 and t.

It is generally expressed in FIT (failure in time) = 10^–9· h^–1 is defined by the relationship :