Defective product sorting (selecting defective products) is the process of selecting products according to their quality levels based on their technical specifications or quality standards before entering the packaging stage, after all products have been produced, to sort out the defective products.
Pre-shipment inspection (PSI), also known as final random inspection (FRI) or finished product quality control, is a comprehensive quality inspection conducted at the end of production, when the goods are 100% finished, at least 80% packaged, and ready for shipment. Customers can also specify whether the products are 100% completed and packaged for inspection.
During production inspection (DPI) refers to the inspection of products during the production process, when the products produced and packaged account for 10% to 30% of the total orders. The purpose is to detect potential quality issues in the production process as early as possible, providing an opportunity for corrective measures in the early stages of production and avoiding the production of a large number of non-conforming products. During production inspection is part of the overall quality assurance plan.