Reliability Analysis of Total Systems Using Component Failure Data

Assessment of total system reliability has been accomplished using component failure data in conjunction with system operating rules and sparing policies. This paper describes the computer simulation used by the Naval Sea Systems Command (NAVSEA) to predict the reliability and availability of each new Naval ship design. The computer program utilizes stochastic simulation to predict reliability, availability, and ordered lists of critical system components. This simulation is unique in that reliability block diagrams for the total system of 500 equipment can be readily translated into compact input coding. Assessment of total ship performance presently takes less than one minute using a vector super computer. This paper describes the methods used to predict long and short-term failures in such equipment as hydrofoil struts and highly complex electronic systems. Long and short-term failure data have been modeled using a Restricted Erlang Distribution for use in the simulation.