Monte Carlo Simulation

Simulation programs such as AvSim+ employ Monte Carlo Simulation techniques to estimate system parameters such as unavailability, number of expected failures, reliability, production capacity, costs etc. The simulation process involves synthesising system performance over a given number of availability simulation runs. Each availability simulation... run in effect emulates how the system might perform in real life based on the input data provided by the user. The input data can be divided into two categories a failure logic diagram and quantitative failure and maintenance parameters. The logic diagram (either a fault tree or a reliability block diagram in the case of AvSim+) informs the simulation program how component failures interact to cause system failures. The failure and maintenance parameters inform the program how often components are likely to fail and how quickly they will be restored to service. By performing availability simulation runs over and over again the computer program can build up a statistical picture of the system performance by recording the results of each run. Monte Carlo Simulation must emulate the chance variations that affect system performance in real life. To do this the computer program must generate random numbers from a uniform distribution. As an example of how simulation works consider an example. Suppose we wish to determine the unreliability of a complex system over a period of 1 year. A simulation model of the system could be developed which emulates the random failures and repair times of the components in the system. The model might be run over the system lifetime of 1 year 1000 times and each time a component fails the model determines whether the system has failed. If the system does not survive on 65 of the lifetime simulations then the system unreliability, F(1), could be estimated as Simulation methods are generally employed in reliability studies when deterministic methods are incapable of modelling strong dependencies between failures. In addition simulation can ...Read More