Throughout this practice the terms detection and prevention apply to quality control systems. A brief description of both is provided to assist the purchaser in the application of this practice.

The detection system relies on inspection as the primary means of controlling the quality of furnished material. Methods include in-process and final inspection. In-process inspection is typically performed by the individual performing the process and generally includes a first-piece inspection by someone other than the operator. Quality-control inspection may perform audit inspections on the process output during the course of the production run. In addition, a final inspection is performed by quality control inspectors according to a prescribed sample plan. The other sample plans utilize zero defects as their acceptance criteria.

The prevention system uses advanced quality planning in addition to many of the techniques used in the detection system. Quality planning incorporates a systems approach to quality control that focuses on defect prevention and continual improvement. In addition, Statistical Process Control (SPC) is usually applied to control the process, to achieve process stability and improve the capability by reducing the variability.

ISO 9001, ISO/TS 16949, ASQ 09001, and Guide F2688 quality system standards, or a combination thereof, are models that may be used in establishing a prevention-based quality system.