I. INTRODUCTION
The Pallet Loading Problem (PLP) is a well-known combinatorial optimization problem which packs small boxes onto a pallet and maximizes the space utilization of the pallet. In general, the boxes' edges must be orthogonal to the pallet's edges, and the boxes can be rotated by 90°. The PLP has many applications in supply chain management and logistics. Hodgson [1] classified the PLP into two cases. One case of the PLP is the Distributor's Pallet Loading Problem (DPLP) which maximized the pallet utilization of packing multiple sizes of boxes onto a pallet. In this paper, we discuss the second case of PLP that is the Manufacturer's Pallet Loading Problem (MPLP). In the MPLP, products produced on large scale by manufacturers are packed into identical boxes, so that only identical boxes are packed onto a pallet. In practical consideration, it is usual to fix the orientation of boxes for stability requirements. The MPLP thus can be regarded as a stack of multiple layers. For each layer, it can be regarded as placing identical small rectangles (i.e. the bottom face of boxes) onto a large rectangle (i.e. the pallet surface) and maximizing the number of small rectangles. The three-dimensional problem becomes a two-dimensional problem which belongs to the two-dimensional, rectangular identical item packing problem (IIPP) class of Wascher's [2] classification.