Dr.  Yeong Wai  Chung
SUNWAY UNIVERSITY,  Malaysia

Title: A Comparison between the Variable Sample Size (VSS) and Variable Sampling Interval

Abstract:

The run sum chart was proposed to improve the performance of detecting shifts in the coefficient of variation, by separating the charting region into different regions where scores are assigned to these regions. Decisions about the in-control status of the process is then made based on the cumulative scores. Further improvements were made on the run sum chart, by varying the sampling interval (VSI) and sample size (VSS) based on the current cumulative scores. Both the VSI and VSS run sum charts show better performance than the run sum chart. This paper compares the performance of the VSI and VSS run sum charts, and found that the VSS run sum charts show better performance in detecting small shifts in, while the VSI run sum charts show better performance for moderate and large shifts.

Biography: