Items arrive from an inventory-picking system according to an exponential interarrival distribution with mean 1.1 (all times are in minutes), with the f rst arrival at time 0. Upon arrival, the items are packed by one of four identical packers, with a single queue kel01315_ch04_121-206.indd 198 05/12/13 3:29 PM Modeling Basic Operations and Inputs 199 “feeding” all four packers. The packing time is TRIA(2.75, 3.3, 4.0). Packed boxes are then separated by type (each box has an independent probability of 0.2 of being international, and the rest are domestic), and sent to shipping. There is a single shipper for international packages and two shippers for domestic packages with a single queue feeding the two domestic shippers. The international shipping time is TRIA(2.2, 3.3, 4.8), and the domestic shipping time is TRIA(1.7, 2.0, 2.7). This packing system works three 8-hour shifts, 5 days a week. All the packers and shippers are given a 15-minute break 2 hours into their shift, a 30-minute lunch break 4 hours into their shift, and a second 15-minute break 6 hours into their shift; use the Wait Schedule Rule. Run the simulation for a single replication of 2 weeks (10 working days) to determine the average and maximum number of items or boxes in each of the three queues (put a text box in your model reporting these output values). Animate your model, including a Resource animation, and a change in the appearance of entities after they’re packed into a box.