n-Unit Warm Standby System with Erlang Failure and General Repair and its Dual

This paper presents two n-unit warm standby systems. In model 1, the operating unit has Erlang failure time and the repair time of a failed unit is general. Model 2 treats the case when the operating unit has general failure time and the failed unit has Erlang repair time. The main paper describes the models and a Supplement presents the integral equations and Laplace transforms of the availability and reliability. Renewal theory is used to set up the equations.