fuzzy process;  quality control;  fuzzy numbers;  Control charts

Aiming at the classification of product quality by the dichotomy of traditional counting control charts, which is inconsistent with the gradual rather than abrupt process of product quality, and it is difficult to meet the situation of fine control of process and product quality, it is proposed that the expert group should subjectively score the product quality, analyze the fuzzy results statistically, form a collective view of product quality in the form of fuzzy numbers, and draw the control chart with this fuzzy number, and use the two methods of possibility measure and necessity measure to monitor the process center trend and ambiguity. In this way, the control status of the process is judged and the process with fuzzy quality characteristics is monitored.