A SUCCESS STORY FOR HIGH-SPEED PACKAGING USING ARENA

THE CHALLENGE

The planned construction of a new airport package sortation facility required the purchase and design of thousands of feet of specialized conveyor, the use of expensive resources to unload aircraft and move material to the sortation facility, and the employ of many operators to unload and sort the arriving packages in a timely fashion. The company decided that a tool that would allow hub planners and engineers to evaluate various operating procedures and aircraft and package arrival rates versus different equipment levels and capabilities would give an extremely accurate description of requirements for the proposed hub. A simulation model was developed by Rockwell Automation to determine optimal equipment and personnel capacities and evaluate various operating procedures.

THE PROJECT

A comprehensive, data-driven Arena model was developed that evaluated the operation of the proposed hub from aircraft and ground truck arrival to the unloading and sorting of packages. The model read Excel data files that described the arrival of aircraft and trucks to the hub; the composition of package type, origin, and destination; and the availability of hub resources. Packages arriving from over 40 origin cities were unloaded from trucks and aircraft and moved by guided transporter to the unload hub where they automatically selected an available unload position. After several unloading steps, unloaded packages were conveyed to an outgoing packages area in one of several destination groups based on the ultimate destination of the package. A detailed animation of the hub was built using an existing AutoCAD drawing provided by the company. The animation showed individual aircraft and truck arrivals, the movement of package containers on tugs to the hub, and the movement of containers and individual packages inside the hub.

THE RESULTS

In addition to the standard output report describing worker, tug, and conveyor utilization; queue time; and queue length, a custom output report was developed that reported the arrival times, unload times, and lateness of each aircraft and truck expressed in Zulu time*. The custom report also reported key hub statistics, such as package flow rates by destination group, to aid in the final design of the conveyor system. Recommendations based on the model results were used to fine-tune the design of the conveyor system inside the hub as well as to modify the relative priorities of various tasks for the unload workers. Another benefit of the model was the evaluation of the effect on total hub throughput of various activities.

(*Zulu time refers to a standard time zone for all carriers, regardless of their geographic location.)