• Draw the demand curves and estimate the season length N; • Computer the moving average MA(N); • Centralize the moving averages; • Get the centralized MA values back on period; • Calculate seasonal factors, and make sure of ct=N. • Divide each observation by the appropriate seasonal factor to obtain the deseasonalized demand • Forecast is made based on deseasonalized demand. • Final forecast is obtained by multiplying the forecast (with no seasonality) with seasonal factors
