) At that time, the concept of "plan-execution-inspection" was introduced. After Deming, the cycle of shewhart further developed into:
Plan-execute-check-handle. Deming cycle is a model of continuous quality improvement.
The lottery method is to number each unit of the survey population first, and then randomly select the numbers.
. . . . . . . . . .
Until enough samples are obtained. It is suitable for transactions with relatively large overall capacity. Because it is simple and easy to realize, it is widely used.