Computation of instant system availability and its applications

Abstract

The instant system availability of a repairable system with the renewal equation was studied. The starting point monotonicity of was proved and the upper bound of is also derived. It was found that the interval of instant system availability monotonically decreases. In addition, we provide examples that validate the analytically derived properties of based on the Lognormal, Gamma and Weibull distributions and the results show that the value of T is slightly smaller than its value defined in Theorem 2. The procedure of using a bathtub as application for this article is also discussed.

Multi‐objective approach to forecast design refresh time due to COTS obsolescence

“…We used point availability performance indicators for the expected instantaneous availability of a system at a given time. System availability ($${E_{Avl}}$$) is a function of MTBF and MTTR values and it represents the probability of the availability for both the system and operator at the time the system is needed for operation 67,68 …”

“…Steady-state availability (Equation 19), also called asymptotic availability, is the limit of the availability function of the availability for both the system and operator at the time the system is needed for operation. 67,68 The reliability of a system (E Rlb ) is a function of MTBF and represents the probability that the system will perform over a required period of time under specific conditions 65,69,70 when needed.…”

“…Operational efficiency is a factor of system's availability, reliability, and maintainability. System availability (E Avl ) is a function of MTBF and MTTR values and represents the probability of availability for the system and operator at the time the system is needed for the operation 67,68.…”