Qual Quant (2013) 47:1803–1812
The effect of the individual chart with variable control
limits on the river pollution monitoring
Pei-Hsi Lee · Yi-Hsien Huang · Tsen-I Kuo ·
Published online: 17 November 2011
© Springer Science+Business Media B.V. 2011
Abstract This study performs a model to evaluate the river water quality monitoring
system. The standard River Pollution Index which includes dissolved oxygen (DO), bio-
chemical oxygen demand (BOD
), suspended solids (SS), and ammonia nitrogen (NH
is collected from years 2006 to 2010 for monitoring of river water quality. Furthermore,
control chart technology can monitor the river pollution and signal the aggravation of water
quality. This study proposes an individual control chart with variable control limits (VCL
individual chart) and veriﬁes this chart can quickly signal the mean change of both normal
can skew populations in statistical performances. In addition, this study also presents a real
case that VCL individual chart is applied on monitoring the water quality of Taiwan’s river.
This case shows the VCL individual chart controls successfully the river pollution, and this
chart is very suitable to apply monitoring the water quality of rivers.
Keywords River pollution · Individual control chart · Variable control limits ·
River pollution index · Statistical design
P.-H. L e e
Department of Business Administration, Chung Yuan Christian University, Chung Li City, Taiwan, R.O.C.
Y.-H. Huang (
) · C.-C. Wang
Institute of Manufacturing Information and Systems, National Cheng Kung University,
Tainan, 701, Taiwan, R.O.C.
Department of Business Administration, National Quemoy University, Kinmen, Taiwan, R.O.C.