Consider an automated security test (e.g., explosives-scanning) station for checked baggage at CVG, the Cincinnati-Northern Kentucky airport. The test workstation is composed of a single machine that has a base-case test capacity of 4 bags per minute. (It takes on average .25 minutes to process a bag.) The squared coefficient of variation, SCV, of the base processing time of the test operation is 0.4624, making the standard deviation equal to 0.17 The machine is subject to random failure with mean time to failure (MTTF or uptime), mf = 8 hours and mean time to repair (MTTR or downtime), mr = 40 minutes. The repair time is exponentially distributed with SCV, cr2 = 1.

1. Calculate the mean and SCV of the effective processing time, te , ce2 and machine availability, after incorporating machine breakdown.

2. Delays caused by the machine breakdowns are frowned upon by customers because they could cause customers to miss their flights. The department has been given $10,000 dollars that they can spend on improvements and they have 2 choices.Which of these choices would you recommend that they pursue and why?(Be sure to provide numeric support for your answer.)

2a. Increase the mean time to failure (MTTF or uptime), mf = 16 hours with all other factors remaining the same.

2b. Decrease the mean time to repair (MTTR or downtime), mr = 20 minutes.The new repair time is estimates to be exponentially distributed with SCV, cr2 = 1.Leave all other factors the same as in the initial problem, i.e – MTTF would be equal to 8 hours with this scenario.