A prototype of a new airport bag-screening system is currently being designed, as in the following f gure. Bags arrive to the system with interarrival times of EXPO(0.25) (all times are in minutes), and are loaded on a load conveyor (75 feet long) and conveyed to an initial scan area. At the initial scan area, the bags are dropped into a chute to wait for the initial scan, which is of duration TRIA(0.1, 0.25, 0.35). Based on the results of the scan, accepted bags (81%) are loaded on an out conveyor (40 feet long) and conveyed to exit the system, whereas rejected bags are loaded on a secondary conveyor (20 feet long) and conveyed to a secondary scan area. At the secondary scan area, the bags are dropped into a chute to wait for a visual inspection, which takes TRIA(0.6,1.2,1.4). After the inspection, they are sent through a secondary scanner that is 10 feet long. This kel01315_ch08_345-378.indd 375 17/12/13 2:07 PM 376 Chapter 8 scan takes 1.2 minutes and only one bag can be in the scanner at a time. At the end of the secondary scanner, the bags are examined by another inspector, taking EXPO(0.4). Based on the results of this secondary inspection, 10% of the bags are sent to a reject area for further inspection, accepted bags are loaded on a third conveyor (20 feet long) and conveyed to exit the system. All conveyors are nonaccumulating with a velocity of 40 feet per minute. Each bag requires one foot of space on each of the conveyors. Develop a model of this system and run it for 2,000 minutes. Use a resource-constrained route to model the second scanner. Visual inspection Secondary scan Chute Chute Initial scan Arriving bags Exit system Rejected bags Exit system The current design calls for a chute capacity of 20 at the initial scan area and a total capacity of 25 at the secondary scan area, not including the bag undergoing the visual inspection. What percent of the time would you expect this capacity be exceeded? (Work this exercise with inf nite chute capacities, and just watch the percent of time the chute capacities contemplated above would be exceeded if they were put into effect.) HINT: Add two time-persistent statistics to collect this information using logical expressions that evaluate to zero if the number of bags is less than the capacity, and to one if the capacity is exceeded.