P-picture, or PS-picture, is a proverb of network or reality. At first, it refers to the use of Photoshop software to beautify, modify, repair and splice pictures in order to achieve the purpose of beauty or spoof. Later, when all drawing or image processing software processes pictures, it can be called p-picture.

Conditions of use:

Although the defect rate control chart is used to control the defect rate of products, it is not suitable for all the defect rate data. When using the defect rate control chart, the following conditions shall be met:

1. The probability of unqualified products is fixed.

2. The front and rear products are independent. If the probability that a product is unqualified is determined by whether the previous product is unqualified, it is not suitable to use P-chart.

3. If the nonconforming products are clustered together, P-chart is not applicable. This problem usually occurs when products are manufactured in groups or groups. For example, in the chemical process of manufacturing rubber products, if the temperature of the oven is set incorrectly, then the whole batch of products produced at that time will have a very high failure rate. If one product is found to be unqualified, other products in the same batch will also be unqualified.