The primary objective of this paper is to increase the performance of a redundant system with two-unit cold standby (one is operative and other is in standby) considering the concept of preventive maintenance (PM), inspection, degradation, priority and maximum operation time. There are two types of servers- ordinary and expert and visit the system immediately whenever needed. The new unit works with less capacity after its repair by ordinary server and is called degraded unit. The degraded unit goes under inspection after its repair. If inspection reveals that repairing of degraded unit at the time of failure is not beneficial to the system, it is replaced with a new one. Priority in repair is provided to the new unit in comparison to degraded unit. The repair activity and PM of new unit is done by ordinary server while the inspection and repair activity of degraded unit is carried out by expert server. If any one or two of new and/or degraded unit(s) are operative then the system is considered in up-state. Preventive maintenance is provided to the system when both the new units are available for use. All random variables follow arbitrary distribution. The regenerative point technique and semi-Markov process is used to obtained the system measures such as mean time to system failure (MTSF), mean sojourn time, availability, busy period of the servers, predicted quantity of visits by using the servers and expected number of visits by server. For a particular case, the numerical results are also evaluated for MTSF, availability and profit of the system model.