On-Shelf Availability (OSA) in the retail industry is the percentage of time a product is available for purchase on store shelves and ready for customers to buy. This metric is critical for evaluating the effectiveness of inventory management, supply chain, and stocking processes. High OSA indicates that products are consistently in stock, reducing the likelihood of missed sales opportunities and customer dissatisfaction. Retailers leverage OSA data to optimize inventory levels, minimize stockouts, and enhance overall customer satisfaction by ensuring that the right products are available when and where customers expect them.