Question

Items arrive from an inventory-picking system according to an exponential inter-arrival with mean of 1.5 (all times are in minutes), with the first arrival at time 0. Upon arrival the items are packed by one of four identical packers, with a single queue “feeding” all four packers. The packing time is TRIA (2.5, 3, 4.5). Packed boxes are then separated by type (20%, international and 80% 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, 4.4), and the domestic shipping time is TRIA (1.8, 2.8, 4.8). This packing system works three 8-hour shifts, five days a week. All the packers and shippers are given a 15 minutes’ short break two hours after the start of their shift, a 30 minutes’ lunch break after four hours from the start of their shifts and a second 15 minutes’ short break after six hours from the start of their shift; use the wait schedule rule. Change in the appearance of entities after they are packed into a box while running the system. Create a simulation model of this system and Save it as HW2-Q4. Run the simulation for two weeks (ten working days) to determine the average and the maximum number of items or boxes in each of the three queues.

simulation using Arena

Answer 1

The inventory packing system that has four shipping agents that acts as servers which works on thee 8 hours shift for 20 days and with exponential inter arrival time with mean (1.5) is given below, upon arrival the items are picked one by one of the four identical packers with single queue feeding all four packers.

The packing time is TRIA (2.5, 3, 4.5).

The model is run for 3 replication out of which first day is considered as warmup period.