Resumen
In the present paper, a reliability model is developed about the profit analysis and Optimization of number of hot standby units for a system working with two operative units. Hot standby works in a similar manner as operating unit means that when an operating unit fails, hot standby unit works with the same efficiency as the operating unit. The optimization of hot standby units is very important factor for any industry/unit/system for increasing the reliability redundancy and achieving the maximum profit. Thus, reliability models with no/one/two/three hot standby units in a system working with two operative units are developed. The cut-off points with regard to revenue, failure rate, etc. have been obtained to determine as to how many standby unit(s) should be there for the system. Comparative study has also been made to see which and when one of these models is better than the other as far as the profitability of the system is concerned. Semi-Markov processes and regenerative point technique have been used to obtain various performability measures.