In this paper availability of an industrial system is simulated, based on Monte Carlo approach. Availability of a system is a nonlinear function of its failure and repair rate. This paper considers a generic system with 4 components. It is assumed that the time between failures and repair time of the components are random variables and have exponential and normal probability distribution functions, respectively. The mentioned system may be in three states: (1) normal operation, half-capacity and failed, according to the failed and intact components. A simulation program is developed which calculates the annual total cost of the system, by producing random variables for components time between failures and repair time and calculates the total cost of the system, based on duration of being system in different states. The effects of variation of system parameters on the total cost are discussed. The results of this research can be used to simulate, predict and optimize the systems reliability and availability.
