What does Acceptance Quality Level really mean? What are its origin?
The concept of Acceptance Quality Level (AQL) has its roots in statistical quality control methods developed in the early 20th century.
AQL's origin thus lies in the need for efficient quality control methods in mass production, particularly driven by military requirements. It has since become a fundamental concept in quality management across various sectors.
- Early 20th century foundations: Statistical quality control methods began to emerge in manufacturing Walter A. Shewhart at Bell Labs developed control charts in the 1920s.
- World War II advancements: The U.S. military needed efficient methods to inspect large quantities of supplies, and statisticians like Harold F. Dodge and Harry G. Romig at Bell Labs developed sampling inspection techniques.
- Military Standard 105: In 1950, the U.S. Department of Defense published MIL-STD-105. This standard introduced AQL and standardized sampling procedures.
- International adoption: The concept spread to other industries and countries post-war. In 1974, the International Organization for Standardization (ISO) adopted similar standards.
- Evolution into ISO 2859: MIL-STD-105 evolved into the ISO 2859 series of standards. These standards are widely used today for attribute sampling.
- Continual refinement: The concept has been refined and adapted over the years. Modern versions balance statistical rigor with practical application in various industries.
The purpose of AQL was the result of the need for a transparent quality control regarding production. It is essential to guarantee the application of a streamlined quality assurance practices worldwide.