A soft control chart based on weighted measurement of fuzzy data

Data for describing human perception frequently appeared in decision processes, which can be modeled by fuzzy sets. For representing a fuzzy set by a crisp value, the weight of importance with respect to members in a fuzzy set with membership levels should be considered. The weighted possibilistic mean (WPM), weighted possibilistic variance (WPV) and the weighted distance between fuzzy numbers have been proposed. In this paper, we propose a general possibilistic mean control chart in view of the possibility theory using the WPM, WPV and the weighted distance.