Efficient module-based modeling for a large-scale AS/RS-AGV system

A method of modeling large-scale AS/RS-AGV systems is proposed in an attempt to describe the AS/RS precisely and flexibly in which a lot of items are stored and retrieved. The system considered in this study consists of the large-scale AS/RS with stacker cranes, the looped track AGV system, aisle conveyors connecting these two systems, and incoming and outgoing conveyors. There are two major stages to model large-scale AS/RS-AGV systems efficiently and to execute simulation experiments. The first stage is to generate a simulation program by placing appropriate modules and inputting the selected parameters such as the number of banks, the number of bays, the number of levels of AS/RS, and the number of AGVs. The second stage is to perform simulation experiments. In the proposed model, every item number puts on each rack, the corresponding number of cases for each item, the time of arriving in the warehouse, and the time of departing from the system are stored and recorded. Generally, it takes a lot of time to build a complex program for a particular type of large-scale AS/RS-AGV system. It is found that simulation/ animation models can be made quickly, by using a module-based modeling method developed in this study.