Yu, Fong-jung; Hou, Jiang-liang - In: Journal of Applied Statistics 33 (2006) 3, pp. 279-290
Duncan's economic model of Shewhart's original x-super-¯ chart has established its optimal and economic application for processes with the Markovian failure characteristic. As the sample statistics show some indications of process variations, the variable-sampling-interval (VSI) control charts...