Kurtosis correction method for X̄ and R control charts for long‐tailed symmetrical distributions |
| |
| Authors: | Pandu R Tadikamalla Dana G Popescu |
| |
| Institution: | 1. Katz Graduate School of Business, University of Pittsburgh, Pittsburgh, PennsylvaniaKatz Graduate School of Business, University of Pittsburgh, Pittsburgh, Pennsylvania;2. Stern School of Business, New York University, New York, New York |
| |
| Abstract: | This paper proposes a kurtosis correction (KC) method for constructing the X? and R control charts for symmetrical long‐tailed (leptokurtic) distributions. The control charts are similar to the Shewhart control charts and are very easy to use. The control limits are derived based on the degree of kurtosis estimated from the actual (subgroup) data. It is assumed that the underlying quality characteristic is symmetrically distributed and no other distributional and/or parameter assumptions are made. The control chart constants are tabulated and the performance of these charts is compared with that of the Shewhart control charts. For the case of the logistic distribution, the exact control limits are derived and are compared with the KC method and the Shewhart method. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 |
| |
| Keywords: | control charts long‐tailed distributions kurtosis correction Shewhart method |
|
|
