3. A study was conducted to evaluate the effectiveness of maintenance crew in repairing steam absorption chillers (SAC) based on total downtime data. The downtimes were recorded as 24, 110, 456, 120, 192 and 52 hours. a. Assuming the repair times can be fitted to a Iognormal distribution, estimate the parameters, and evaluate the probability that the maintenance crew will be able to complete the repair work in 96 hours. [8 marks] b. Availability is one of the important measures for repairable systems. The maintenance records for the SAC indicate that there is 1 scheduled maintenance per 1000 hours of operations and the demonstrated failure rate of 0.6 failures per 1000 hours. It takes an average of 4 hours to attend to unscheduled downtimes. The preventive maintenance downtime is 8 hours on average. Assuming the logistics and administrative delays add extra 10 hours to the total maintenance time, assess the achieved availability for the system. [7 marks] 0. The consequence of unscheduled downtime is high especially in oil and gas operation and safety. Propose and illustrate with example, a suitable reliability centered maintenance programme that can be adopted to predict and prevent failures. [10 marks]