IEVref: 192-05-08 ID: Language: en Status: Standard Term: instantaneous failure intensity Synonym1: failure intensity [Preferred] Synonym2: Synonym3: Symbol: z(t) Definition: limit, if it exists, of the quotient of the mean number of failures of a repairable item within time interval (t, t + Δt), by Δt, when Δt tends to zero $z\left(t\right)=\underset{\text{Δ}t\to 0+}{\text{lim}}\frac{E\left[N\left(t+\text{Δ}t\right)-N\left(t\right)\right]}{\text{Δ}t}$ where N(t) is the number of failures in the time interval (0, t), where E denotes the expectation. Note 1 to entry: Other terms used for failure intensity are “rate of occurrence of failures”, and “failure frequency”. Publication date: 2015-02 Source: Replaces: Internal notes: CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: