Profit comparison of two stochastic models each pertaining to a two-unit standby oil delivering system with different modes of failure

This paper deals with the profit comparison of two stochastic models A and B each consisting of two unit standby oil delivering system with different modes of failure (i.e., direct failure or via partial failure). In Model 1 the system has only one mode of failure that unit fails completely only by direct failure. In Model II System has two modes of failure i.e. the unit can fails completely either directly from normal mode or via partial failure. Initially one unit is operative and the other is standby. On the complete failure of both the units there is a provision of switching over to the other similar system. This practical situation may be observed in an oil refinery plant. Techniques of the semi-Markov processes and regenerative processes are used to obtain various measures of system effectiveness and profit incurred. A comparison of model 1 is made with model 2 through graphs.