Introduction

A company specializing in automated storage/retrieval systems (ASRS) engineered a new type of motor to drive a vehicle on a rail system. The company’s main customer base consisted of warehouses and distribution centers that retrieved orders manually by fork truck or by hand. By installing an ASRS with this new type of motor, the company believed that distributors could significantly increase the number of orders they could fulfill each day, with less operator overhead. Yet the company still needed some way of proving to their potential customers that this new motor would in fact be a major improvement. The company decided to use simulation as a strategy for selling its motor. By showing potential customers a 3D simulation model in which an ASRS fulfills orders instead of a fork truck or by hand, and by having that model report, in real-time, simulation results for throughput of the model, salespeople could both wow customers with “state-of-the-art” virtual reality 3D graphics, as well as show that there is real benefit to investing in the new ASRS system.

Simulation

The company wanted a simulation model that shows intricate kinematical motion of ASRS vehicles, and that is also statistically sound in its results. The company proposed to model a beverage distribution center that supplies many of the restaurants in a metropolitan area. Inventory is organized into racks containing full pallets of Coke, Pepsi, Beer, etc., each pallet containing just one type of beverage. A pallet consists of between 5 and 15 vertically stacked layers. Each layer contains several packages of beverages, but is shrink-wrapped together as one piece. Orders are made in layers. For example, a given order may be for 2 layers of Coke, 4 layers of Coors, 1 layer of Pepsi, etc. The ASRS vehicle contains a horizontal square frame that can extend from the center of the ASRS vehicle over the appropriate pallet, drop down on the layer(s), squeeze them, lift them up, contract the square frame back to the center of the ASRS vehicle, and finally drop them down onto a pallet. The company needed all of these motions to be visually true-to-life in the simulation. As inputs for this model, the company wanted to be able to easily configure the acceleration, maximum speed, deceleration, and load time of the vehicle, as well as the orders coming into the warehouse. For results, the company wanted to know the average number of orders per hour and picks per hour.

Conclusion

A specialized ASRS vehicle object was developed for the company that correctly simulates the kinematics of picking up and dropping off pallets and layers in this distribution center. A model was also created to show the operation of this specialized object in the distribution center. The impressive visual appeal of this model, as well as the presentation of real-time statistical outputs gave the company a better ability to sell its new motor. The company continues to show this model at vendor booths of trade shows in its industry.