This paper presents a new class of nonlinear control charts which resp
ond quickly to small shifts and jump patterns in tme series. The under
lying disturbance models for the control charts are nonlinear extensio
ns of the IMA(1,1) model. The Kalman filtering algorithm generates Bay
esian estimates of the process level for the control chart plotting. T
he single-parameter chart is identical to the EWMA, while the two- and
three-parameter designs are much more effective in detecting small sh
ifts mixed with local trends. The nonlinear control charting scheme is
also capable of detecting a mean shift in independent observation.