A two component two unit standby system with correlated failure and repair times

Abstract

The paper deals with a two non-identical unit standby system model having two units- A and B, each consists of two non-identical components arranged in series network. Initially, unit- A is operative and unit-B is kept as cold standby. Each unit of the system has two modes — Normal (N) and Total failure (F). When unit- A is failed, the standby unit-B starts operation. A single repair facility is available with the system to repair the failed components of both the units. Unit- A gets priority in repair over the unit- B. If the repair of a component of unit- B is restarted after interruption, it is assumed to be pre-emptive repeat type, i.e., the time already spent in repair goes to waste. Each repaired unit works as good as new. The joint distribution of failure and repair times of each component of both the units is assumed as bivariate exponential. Various measures of system effectiveness of interest to system designers and operations managers are obtained by using regenerative point technique.

Keywords:

• Transition probability
• MTSF
• reliability
• availability
• busy period