This paper deals with the probablistic analysis of a system subject to stresses. The system consists of a basic unit and a standby and is provided with a service facility to carry out maintenance, inspection prior to repair and repair of the units in the system. The operating unit is sent for maintenance as soon as its strength, after being hit by a stress, falls below a specified critical value, the strength being assumed to be deterministic. The operating unit may also fail on any stress by virtue of the stress exceeding the strength. The failed unit is subject to inspection prior to repair to ascertain the type of repair the unit has to undergo. The stress experienced by a unit is assumed to be a random variable governed by a probability law. The time between successive stresses and the time for maintenance, inspection and repair are random variables governed by probability laws. Explicit expressions for various system characteristics have been obtained using the state-space method and the regeneration point technique.