Other methods are available that an

Other methods are available that analyze all past data, using one model to forecast demand for all of the seasons. We describe only the multiplicative seasonal method, whereby an estimate of average demand is multiplied by seasonal factors to arrive at a seasonal forecast. The four-step procedure presented here involves the use of simple averages of past demand, although more sophisticated methods for calculating averages, such as a moving average or exponential smoothing approach, could be used. The following description is based on a seasonal pattern lasting one year and seasons of one month, although the procedure can be used for any seasonal pattern and season of any length.