Kurtosis correction method for variable control charts - A comparison in laplace distribution

A variable quality characteristic is assumed to follow the well known laplace distribution. control chart constants for the process mean,process dispersion based on a number of sub group statistics including sub group mean and range are evaluated from the first principles. limits obtained through kurtosis correction method are borrowed from tadikamalla and popescu (2003). the performance of these sets of control limits is compared through a simulation study and the relative preferences are arrived at. the methods are illustrated by an example.