Recently, Clutter released a feature to present the optimal pallet composition for a given Stock Keeping Unit (SKU) in our internal iOS app for our warehouse team. It enables us to efficiently utilize warehouse and truck space and save time loading items onto pallets. This article will cover our approach to the pallet loading problem and briefly summarize the paper we implemented.
A good solution must produce demonstrably optimal results and be easy to understand for the end user, Clutter’s warehouse employees. This led us to the pallet loading problem. With iOS SpriteKit as the visualization tool, we were able to create a solution that meets these success criteria.
Before diving into the solution, we should define what an optimal pallet arrangement is. There are a number of formulations of the pallet loading problem with varying complexity. From optimizing a 3D composition with arbitrary rotations and boxes of different sizes, we pared the problem down to finding the optimal way to arrange the maximum number of identical boxes in a single, flat layer on a pallet. Or in other words, the composition of identical rectangles in a larger rectangle, with 90° rotations. This makes it easy for someone to follow a diagram of the optimal composition and stack to a given height.
You can try it out for yourself with this realistic example! Given a SKU with dimensions 14” x 6” and a pallet with dimensions 48” x 40” (the size of a standard pallet), determine the composition that will fit the maximum number of that SKU.