PROFIT ANALYSIS OF A SYSTEM WITH 2-UNITS HAVING GUARANTEE PERIODS ANDDELAYED OPERATION OF STANDBY

A single-server two-unit (one priority, p and the other ordinary, o) c old standby system model is investigated. The p-unit has four differen t modes-excellent (E), good (G), satisfactory (S) and total failure (F )-of which the first three are operative modes while the o-unit has on ly two modes-normal (N) and total failure (F). When the p-unit enters F-mode the repairman starts the operation of the o-unit. The time take n to start the operation of the o-unit is not negligible and is assume d to be a finite quantity T(r). The failure time distributions of the o-unit and the p-unit in the E-mode are taken to be truncated exponent ial while all the other time distributions are negative exponential ov er the range 0 to infinity. By identifying the system at suitable rege nerative epochs, the profit functions under two different policies are obtained.