Title :
ESCAF for MTBF, Time Evolution, Sensitivity Coefficients, Cut-Set Importance, and Non-Coherence of Large Systems
Abstract :
ESCAF - an "Electronic Simulator to Compute and Analyze Failures" ¿ is a commercially available desktop apparatus, now in wide use, which employs special electronic circuit boards to simulate and analyze a system by methods and procedures that are easy to learn and apply by engineers with only very limited knowledge of electronics or computing. The apparatus has been used mainly to determine the cut sets and failure probabilities of very large systems, with up to 416 components, offering possibilities well beyond those of conventional methods of analysis. This article defines new parameters that can be calculated by ESCAF, including novel parameters (degree of non-coherence). It also explains how ESCAF determines, for systems of any complexity, measures that were previously inaccessible for other than very simple systems: ¿ Mean time between failures, mean time to failure, mean time to repair, failure and repair intensities, and equivalent failure or repair rates as a function of time, ¿ Time-derivative of the unavailability and/or failure probability, ¿ Sensitivity coefficients indicating the importance of each component in probability calculation, ¿ Importance of each minimal cut set (for coherent systems), ¿ Whether a system is coherent or not. The first three results can be obtained regardless of system coherency. All results are obtained very simply and very rapidly.