Title: Horizontal cumulative variance chart: a quality control scheme monitoring shifts in process variation
Authors: Xia Pan
Addresses: Lingnan College, Sun Yat-sen University, China
Abstract: In this study, we consider a new quality control scheme named horizontal cumulative variance (HCUV) which is designed to monitor the shifts in process variation. We start our discussions with the statistical properties of the distribution of cumulative squares then further to that of cumulative variances, and the mathematical measures to have a horizontal shape of these control schemes. We then propose HCUV. To illustrate the charts, we first run HCUS and HCUV with simulated data. We finally apply HCUV to chemical process data obtained from a real chemical manufacturing company. The illustration suggests that the HCUV scheme have the potential for practically monitoring changes in process variation.
Keywords: statistical process control; SPC; horizontal cumulative variance chart; HCUV; variation shift; control charts; quality control; process variation; monitoring; chemical processes; chemical manufacturing.
DOI: 10.1504/IJISE.2017.081521
International Journal of Industrial and Systems Engineering, 2017 Vol.25 No.2, pp.265 - 277
Received: 14 Feb 2015
Accepted: 23 Mar 2015
Published online: 11 Jan 2017 *