Non-Normality and the Fuzzy Theory for Variable Parameters Control Charts

Chaowalit Panthong, Adisak Pongpullponsak

Abstract

This paper applies the fuzzy theorem to non crispy data in creating the control charts.  The triangular fuzzy membership function with -cut is introduced to eliminate less important data.  The non normality data are generated to evaluate the performance of the variable parameters control charts (VP), the fuzzy variable parameterscontrol charts (FVP), and the fuzzy variable parameters control charts by weighted variance method (FVP-WV).The performances of the variable parameters control charts  are  Average Adjusted Time to Signal (AATS), Average Number of Observations to Signal(ANOS), and Average Time to Signal (ATS), the fuzzy variable parameters control charts by weighted variance method (FVP-WV)shows the best in every aspect.