The operation techniques and activities taken to meet the quality requirements are called quality control. That is to say, quality control is to eliminate the factors that cause unqualified or unsatisfactory results at all stages of the quality loop by monitoring the quality formation process. Various quality operation techniques and activities adopted to meet quality requirements and obtain economic benefits.

Quality control is an activity in terms of technical measures and management measures taken to make products or services meet quality requirements. The goal of quality control is to ensure that the quality of products or services can meet requirements (including explicit, habitually implied or mandatory regulations).

In the enterprise field, quality control activities are mainly production site management within the enterprise. It has nothing to do with whether there is a contract or not. It refers to the activities of technical measures and management measures for controlling to achieve and maintain quality. Quality inspection is subordinate to quality control and is an important activity of quality control. Internationally, quality control objects can set "witness points" or "stop points" according to their importance and supervisory control requirements. "Witness point" and "stop point" are both quality control points. Because of their different importance or quality consequences, their operating procedures and supervision requirements are also different.