A Monte Carlo Fortran computer program was developed that uses two variance reduction techniques for computing system reliability applicable to solving very large highly reliable fault-tolerant systems. The program is consistent with the hybrid automated reliability predictor (HARP) code which employs behavioral decomposition and complex fault-error handling models. This new capability is called MC-HARP which efficiently solves reliability models with non-constant failures rates (Weibull). Common mode failure modeling is also a specialty. Platt, M. E. and Lewis, E. E. and Boehm, F. Unspecified Center COMPUTERIZED SIMULATION; FAILURE; FAILURE MODES; FAULT TOLERANCE; MONTE CARLO METHOD; RELIABILITY; RELIABILITY ANALYSIS; APPLICATIONS PROGRAMS (COMPUTERS); MARKOV CHAINS; RELIABILITY ENGINEERING...