MTBF (mean time between failures) is the expected time between two successive failures of a system. Therefore, MTBF is a key reliability metric for systems that can be repaired or restored. MTTF (mean time to failure) is the expected time to failure of a system. Non-repairable systems can fail only once. Therefore, for a non-repairable system, MTTF is equivalent to the mean of its failure time ...

This paper documents a simulation study undertaken to gain insights into the Vari-Metric multi-echelon repairable inventory optimization method. The method was analyzed in the context of the Coast Guard’s fleet of fixed and rotary wing aircraft, for which operational availability is the key performance metric. Failure rates of parts in this system exhibit variance-to-mean ratios higher than one...

JDMS, Volume 2, Issue 2, April 2005 Pages 87–100 © 2005 The Society for Modeling and Simulation International Traditional multi-echelon inventory and readiness-based models have not fully examined the ability of effective transportation utilization to reduce cost, delay times, and improve readiness in the overall military logistics network. In this paper, we develop a simulation-based methodolo...

In this paper, we analyze spare parts supply for a system with a “k-outof-N” redundancy structure for key components, different standby policies (cold, warm and hot standby redundancy) and local spare parts inventories for sub-components. We assume multiple part types (sub-components) that fail randomly with exponentially distributed interfailure times. Due to the standby policies and the limit...

RRAM (Redundant Random Access Memory) is a RAM with redundant spares included in the chip. Because of the row/column organization of memory cells in RAMs, these spares are organized as rows and columns. Memory cells which are faulty can be repaired by the spare rows, spare columns and their combinations. Because additional cost of incorporating spares and repairing, it is usually advantageous t...

Compressed air energy storage (CAES) is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. This study proposes a CAES-CC system, which is based on a conventional ...

Reconfigurable chips are fabricated with redundant elements that can be used to replace the faulty elements. The fault cover problem consists of finding an assignment of redundant elements to the faulty elements such that all of the faults are repaired. In reconfigurable chips that consist of arrays of elements, redundant elements are configured as spare rows and spare columns. This paper consi...