RELIABILITY MEASURES OF A SYSTEM OF TWO NONIDENTICAL UNITS WITH PRIORITY SUBJECT TO WEATHER CONDITIONS
In this paper, reliability measures of a system of two non-identical units operating under normal and abnormal weather conditions are obtained in steady state using semi-Markov process and regenerative point technique. Initially, one original unit (called main unit) is operative while the other substandard unit (called duplicate unit) is taken as spare in cold standby. Each unit has direct complete failure from normal mode. There is a single server who visits the system immediately to carry out repair of the failed unit. However, repair of the failed unit is not allowed in abnormal weather while system remains operative. Priority is given to operation and repair of main unit over duplicate unit. The distributions for failure times of the units and time to change of weather conditions are taken as negative exponential while that of repair time of the units are arbitrary. All random variables are statistically independent. The results for some important reliability measures have been analyzed graphically for arbitrary values of various parameters and costs.