RELIABILITY AND PROFIT ANALYSIS OF 2 SINGLE-UNIT MODELS WITH 3 MODES AND DIFFERENT REPAIR POLICIES OF REPAIRMEN WHO APPEAR AND DISAPPEAR RANDOMLY

Cost-benefit analysis of a single-unit system with three possible modes of the unit-normal (N), partial failure (P) and complete failure (F)-is carried out. The paper consists of two models: in model 1, the unit goes under repair (if a repairman is available) the moment it fails partially, whereas in model 2 the unit goes under repair at complete failure. The repairman appears in, and disappears from, the system randomly. A comparison between these two models after calculating MTSF and profit has also been made.