Reliability and availability of a standby system with common cause failure

The reliability and availability are considered for four series configurations with both warm and cold standby with the existence of common cause failure of the system at all states. The mean time to failure (MTTF) and steady state availability are derived for all configurations. It is assumed that the time between failures and repair time to be exponentially distributed. Examples are presented for comparing all configurations for specific values of the different parameters under various costs of the components. The configurations are ranked based on preference with respect to different parameter ratios.