A milling machine has 3 different bearings that fail in service.The distribution of the life of each bearing is identical, as shown in Table 21. When a bearing fails, the mill stops, a repairperson is called, and a new bearing is installed. The delay time of the repairperson’s arriving at the milling machine is also a random variable having distribution given in Table 22. Downtime for the mill is estimated at Rs.10 per minute.The direct on-site cost of repairperson is Rs.30 per hour; It takes 20 minutes to change one bearing, 30 minutes to change 2 bearings, and 40 minutes to change 3 bearings; cost per bearing Rs.32. A proposal has been made to replace all 3 bearings whenever a bearing fails. Management needs an evaluation of the proposal; the total cost per 10,000 bearing-hours will be used as the measure of performance.