This paper investigates a mathematical model for a computer communicat
ion system of two units-a computer and a controller. Each unit has n c
omponents, i.e. the computer has an n-processor while the controller h
as n converters. The amount of change in the computer or controller de
pends on the change in the components of these two units. These change
s bring the system to either a partially failed state or a completely
(totally) failed state. Failure rates are assumed to be negative expon
ential; recovery and repair rates are arbitrary. Various cost-related
reliability measures have been studied using the regenerative point te
chnique.