| Two different control charts are proposed based on weighted representativevalue(WPM) as well as a weighted area method. The weighted possibilistic meanas a sort of representative values of the fuzzy attribute data has been applied in con-structing a control chart. In the second way, we design a control chart according tothe weighted area of the fuzzy sample.Methods based on WPM may reduce the losses of information arisen from fuzzydata transforming a lot. Furthermore, weighted area method also prevents the lossesof information by avoiding data transforming.Adaptive control charts can be used to improve the efficiency of the controlcharts. And EWMA control chart behaves much better than Shewhart control chartand CUSUM control chart. So in this paper, we focus on the adaptive EWMA controlchart based on the former two methods.The main work of this paper can be summarized as follows1. The method based on WPM is proposed for designing the control charts. Andthe WPM method is compared with the other representative values method with anumerical example.2. The method of computing the areas of the fuzzy samples presented by trape-zoidal fuzzy numbers fall between the control limits is improved. And this method isextended to the situation where the samples are presented as LR?fuzzy numbers.3. Direct fuzzy method based on weighted areas of the samples, which are ex-pressed by LR?fuzzy numbers, is proposed. A numerical example is used to illustrateits peculiarity and advantage.4. The adaptive EWMA control chart is designed based the WPMs and theweighted areas of the fuzzy samples.
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