Demand forecasting: procedure of Winters
The forecasting procedure of Winters for trend and seasonal demand is applied.
Initial value for the seasonal factors may be computed with the help of the
module time series analysis.
Initial values can be computed in the module Time series
analysis.
Symbols:
Alpha |
smoothing constant for the base level |
Beta |
smoothing constant for the slope |
Gamma |
smoothing constant for the seasonal indices |
b0(t) |
base level of the tren line in period t |
b1(t) |
slope of the trend line in period t |
s(j) |
seasonal factor for seasonal period j |
Y(t) |
observed demand in period t |
P(t) |
forecasted demand for period t |
Literature:
- Tempelmeier (2005)
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