In quality control, random inspection has become the mainstream inspection method. The core reason is that it maximizes cost control and efficiency while ensuring inspection effectiveness, and also maintains the scientific nature of sampling inspection. Specifically, this can be analyzed from the following dimensions:

I. Balancing Cost and Efficiency: Avoiding the Waste of Resources in 100% Inspection

Limitations of 100% Inspection: While 100% inspection ensures the quality of every product, it has significant drawbacks:

High Time Costs: For mass-produced products (such as plastic bags, electronic components, and daily necessities), 100% inspection consumes a large amount of manpower and time, severely delaying delivery dates, especially unsuitable for the "on-time delivery" requirements in international trade.

High Labor Costs: 100% inspection requires a large number of quality inspectors, and prolonged repetitive inspections can easily lead to visual fatigue or judgment errors, reducing inspection accuracy.

Destructive Testing Cannot Be Performed by 100% Inspection: Some inspection items are destructive (such as tensile strength testing of plastic films and voltage resistance testing of electrical appliances). 100% inspection would directly consume all finished products, making it completely impractical. The advantages of final random inspection: Final random inspection involves selecting a representative sample for testing according to statistical sampling standards (such as GB/T 2828, ISO 2859) after all production is completed and before shipment.

It infers the quality of the entire batch of products from a small sample, significantly shortening inspection time and reducing manpower input.

For destructive testing, sampling inspection is the only feasible method, verifying product performance without wasting the entire batch of goods.