All through the life-cycle of a standby system, it is very challenging to keep a standby unit workable. It may be fatal if the standby found non-workable when needed. This paper evaluates the performance of a standby system working under two primary constraints by underlining the condition of the spare unit in standby mode. The first constraint is the maximum redundancy time for the standby and the second is maximum operation time for the operating unit. The standby unit fails on exceeding the maximum time threshold and thereafter the decision about its repair/replacement is subjected to the inspection. While after surpassing the maximum operating time limit preventive maintenance is carried out for the operating unit. To study the long-run performance or life-cycle of the system various performance indices have been analyzed using the theory of discrete-state continuous-time semi-Markov regenerative processes. Exponential, Rayleigh and Weibull probability distributions are used to study the system performance numerically.