3.1.1. Coding

Considering that coding of rack locations, which is much longer than storage and retrieval tasks, increases the complexity of the algorithm and reduces the search efficiency, coding is performed mainly for the storage and retrieval tasks, as shown in Figure 5. The number of storage and retrieval tasks is used as the coding length, and the tasks are arranged in the order of execution. In the retrieval tasks, it is randomly selected from the corresponding material locations in AS/RS. In the storage tasks, it is randomly selected from the free locations in AS/RS.


**Figure 5.** Coding diagram.
