vuuct has a Mean Time Between Failures (MTBF) of 30 hours and has a Mean Time To Repairs (MITR) of 5 hours. Product B has a MTBF of 40 hours and has a MITR of 2 hours. (i) Which product has the higher reliability? Which product has greater maintainability? (ii) Which product has greater availability? x31 Product B, with higher MTBF (i.e. 40 hours) than Product A (i.e. 30 hours), is more reliable since it has lesser chance of failure during servicing. BY MITR we mean the time taken to repair a machine and put it into operation. Thus Product B, with lesser MITR (i.e. 2 hours) than Product A (i ... 5 hours), has greater maintainability. (c) Availability of a machine/product = MTBF + MITR MTBF Therefore, Availability of Product A = 30/ (30+5) = 30/35 = 85.714% Availability of Product B = 40/(40+2) = 40/42 = 95.238% Hence, Product B has more availability. Maharashtra Trucking Company (MTC) has a fleet of 50 trucks. The past data on the breakdown of the trucks show the following probability distribution (for a new truck as well as for one which has been repaired after a breakdown) Months after Maintenance Probability of Breakdown 0.10 0.20 0.30 0.40 2 3 4 Each breakdown costs 3,000 on an average; which includes cost of time lost and cost of materials and manpower. The manager of MTC knows the importance of preventive maintenance. He estimates the costs of the preventive maintenance to be 500 per such preventive action. What should be the appropriate maintenance policy in terms of the mix of preventive and breakdown maintenance