The rack orientation and curvature problem for retailers

The layout of a retail store directly affects the products to which shoppers are exposed, and ultimately their purchase. Optimizing a layout to increase product visibility can directly benefit both the retailer (via increased revenue) and the shopper (via increased satisfaction). We introduce the Rack Orientation and Curvature Problem, which determines the orientation and curvature of each rack in a layout to maximize the expected marginal impulse profit (after discounting for floor space cost). We account for the dynamic interaction between a walking shopper’s field of regard and a layout of racks filled with products. As several constraints in the optimization model cannot be expressed in a closed analytical form, we propose a particle swarm optimization-based solution approach and, subsequently, conduct a comprehensive experimental study using realistic data. Layouts with either high-acute and straight-to-medium-curved racks, or high-obtuse and high-curved racks, appear to dominate common rack layouts with orthogonal and straight racks; increases of over 23% can be realized depending on the location policy of products. Sensitivity of these solutions to shopper volume, cost of floor space, travel direction, and aspect ratio is also evaluated. Retailers can use our approach to quantitatively evaluate new rack designs or benchmark existing ones.