Availability Of Series System Research Articles

Optimal redundancies for reliability and availability of series systems

Five different series system configurations with standby units are compared based on their overall reliability and availability. The time-to-failure of a component and its repair time are assumed to have the negative exponential distribution. The mean time-to-failure, MTTF, and the steady-state availability, A T (∞), are obtained for the first three simple configurations and comparisons are performed. For all five configurations, comparisons are made based on assumed numerical values given to the distribution parameters, as well as to the cost of the components. The configurations are ranked based on: MTTF, A T (∞), cost and cost-benefit where benefit is either MTTF or A T (∞).

Availability of Series Systems with Various Shut-off Rules

In series systems (reliability block diagram), failure of any component leads to system failure. However, depending on the shut-off rule, some components may continue to operate with the system down. In this paper we consider several shut-off rules for series systems performance. We calculate limiting system availability under these shut-off rules. In particular, availability results for 2-and 3-unit systems with constant failure and repair (hazard) rates are extended to systems of arbitrary size.