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EWMA
Forecast
The prediction of the process
for time t, based on the exponentially weighted moving average at time t-1.
Used in the Wandering Mean EWMA Chart.
for 2 < t < m+1
where:
- xt-1 is the prior
observation included in the analysis
- the Starting value
(value at time t=0) is either the Target value or process mean value
(user defined)
-
is the value of the Weighting Factor (user defined). An optimal value
of lambda can be determined that minimizes the Prediction
Error
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