A simulation-based reliability prediction model for conceptual design

During the early stages of conceptual design, the ability to predict reliability is very limited. Without a prototype to test in a lab environment or field data, component failure rates and system reliability performance are usually unknown. A popular method for early reliability prediction is to develop a computer model for the system. However, most of these models are extremely specific to an individual system or industry. In this paper, a generic simulation model is presented for predicting system reliability without knowing the exact failure rate for the components in the system. The simulation model estimates mission reliability, average time to failure for the system, and average mission cost. The estimates are based on the number of series subsystems and active or stand-by components for each subsystem, known component failure rates, triangular distribution parameters for components with unknown failure rates, mission length, and component and mission costs. The result is a tool that engineers can use to predict system reliability performance early in the system design process.