Presenting a Model of Fuzzy Statistical Process Control with Fuzzy Mode Method to Control Product Defects

The classical control charts by using precise and specified data divide the production process into two groups: in-control or out of control, while the fuzzy sets with the definition continuous and cohesive membership functions and also using ambiguous and vague fuzzy numbers (triangular and trapezoid), It introduces different levels of decisions for the decision makers. In this paper, using the fuzzy mode for drawing fuzzy control charts beside using indefinite data and information based on the personal's experience and subjectivity has defined the multiple levels of the quality of product (in-control, rather in-control, rather out of control or out of control) in the production firms which states the real conditions of the production.