Comparison of profit of a two-unit cold standby system with instruction time

The comparison of profit of a two-unit cold standby system with instruction time have been analysed. We have taken a two-unit cold standby system having an expert repairman and his assistant. The assistant repairman can repair a failed unit only after getting instructions from the expert. If the expert repairman is engaged in repairing a failed unit and at that time second unit fails then he leaves the repair in the state of temporary suspension and starts giving instructions to his assistant for repairing the second unit. Also the profit is calculated for a particular case where the repair time and instruction time distributions are exponential. Graphs are plotted and the model is compared with another model in which both the repairman work independently.