Reliability analysis of a retrial machine repair problem with warm standbys and a single server with N-policy

This study analyzes the system reliability of the retrial machine repair system with M operating units, S warm standby units and a single repair server with N-policy. Failure times of operating units and standby units are assumed to have exponential distributions with rates lambda and eta respectively. When the repair server normally operates in serving failed units, it is subject to breakdown. The time to failure and the repair time for the single server are assumed to follow exponential distributions. When the server is broken down, it can also provide partial repair service with lower service rate. The repair times of failed units also have exponential distributions. Extensive numerical experiments are designed and executed to realize how performance measures are affected by the change of each system parameter.