A method includes disposing, by using a transport module of a workpiece storage system, a first workpiece on a first workpiece carrier; disposing, by using the transport module, the first workpiece carrier with the first workpiece in a workpiece container; disposing, by using the transport module, a second workpiece in the workpiece container, wherein the first workpiece and the second workpiece have different sizes; and transferring, by using the transport module, the workpiece container containing the second workpiece and the first workpiece carrier with the first workpiece to a stocker to store the workpiece container.