This study deals with cost analysis of a two-unit cold standby redundant system with preventive maintenance.The random failure occurs at random times which follow an exponential distribution and also the repair time are assumed to be exponentially distributed. Using the Kolmogorov's forward equations method. Several reliability characteristics are obtained. The mean time to system failure (MTSF) and the profit function are studied graphically. Key words:Cost analysis, steady-state availability, mean time to system failure (MTSF), preventive maintenance (pm) and the kolmogorov's forward equations method

This study discusses the reliability of two units cold standby system with single repair. For achieving high reliability of the system, the operative and the standby units are interchanged at random epochs and additional preventive maintenance of operative and the standby units also. After the repair, the unit is sent for inspection to decide whether the repair is satisfactory. In case the repair is found unsatisfactory the unit is again sent for post repair. Using a regenerative point technique, various measures of system effectiveness are obtained

This study deals with the reliability and availability characteristics of two different series system configurations. The second system differs from the first system due to the additional feature of preventive maintenance. The failure times of a components are assumed to be exponentially distributed with parameters α,β,α' and β', respectively. The replacement time distribution of each server is also exponentially distributed with parameters γ, δ and θ. We derive the mean time-to-failure, MTTF, and the steady-state availability,A_T(∞) for the two systems using linear first order differential equations and perform comparisons theoretically and graphically to observe the effect of the preventive maintenance on system performance

In this study we investigated the cost-benefit analysis of a two-unit cold standby system with two-stage repair of a failed unit. We discuss the concept of waiting time with two-stage repair for a two-unit cold standby system. The repair process is divided into two stages. In the first stage, the repairing process of the unit is started but it does not get completed; instead the process is completed in the second stage. The elapsed time between two stages is called the waiting time. Techniques of regenerative point processes have been used to measure the effectiveness. The time dependent availability, steady state availability, reliability, (MTTF) and profit function were obtained numercially and graphically. The MTTF, the steady-state availability and the profit function decreased with respect to the increase of failure rate and waiting rate.

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