I. Introduction
The U.S. Army Corps of Engineers, Power Reliability Enhancement Program sponsored a survey effort to determine the various reliability/availability (R/A) analysis software tools available for utility, commercial and industrial electrical and; mechanical R/A analysis. The research quickly indicated that many users were utilizing a wide variety of analysis tools and techniques with different results. Although. many users were using different analysis techniques, the only recommended methodology presented in IEEE Std 493 “Gold Book” since 1980 was the “series and parallel” reliability methodology and the minimal cut-set method which estimated the frequency and duration of load point interruptions.