Production Monintoring and In-line Inspection refers to the supervision of the production process, following up on production progress, and conducting product quality inspections on various processes of the product during the production process, including the inspection of finished and semi-finished products. The purpose is to timely identify and correct problems at each stage of production, thereby ensuring that the quality of the final product meets the requirements. Unlike final product inspection, inline inspection is conducted continuously during the production process, including inspection of finished products and inspection of semi-finished products, involving various production processes and stages where problems may occur. It can be dealt with immediately when problems occur to avoid producing a large number of unqualified products.

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.