An optimal operation policy for n-server stand-by systems operating in real time is obtained. It appears that, under certain conditions, such a policy is achieved by successive total use of each server capacity. The analysis is perfromed in two stages: (1) a non-stop operating system is treated, and then (2) a general system, which operates only in response to orders. As demonstrated, such a consecutive approach seems to be highly promising for the analysis of complicated system involving preventive maintenance and operating in real time.
