Availability and profit analysis of a two-unit cold standby system for general distribution

This paper discussed a two-unit cold standby system by considering the concepts of degradation, inspection, preventive maintenance (PM), and priority. The unit works as a reduced capacity after its repair and is called degraded unit. There is a single repairman who visits the system immediately. The repairman inspects the failed degraded unit to see the feasibility of repair. If the repair of the degraded unit is not possible, it is replaced by new unit. PM will provide to the system when both the units are degraded and available for use. Priority for operation and repair is provided to new unit over-degraded unit. Various reliability characteristics such as mean time to system failure (MTSF), availability, busy period of the repairman, expected number of visits by the repairman, and profit of the system have been obtained using regenerative point graphical technique. For particular case, the results for MTSF, availability, and profit function are obtained considering exponential, Rayleigh, and Weibull distributions for all random variables. Subjects: Applied Mathematics; Engineering & Technology; Mathematics & Statistics; Science; Statistics & Probability; Technology