The values of A and B can be chosen independently
depending upon how fast the level of sales
changes and how fast the seasonal patterns change.
A high value of A will minimize lag in following
changes in the level of sales, but there will be less
smoothing of random fluctuations.A high value of
A gives weight only to very recent observations
thereby minimizing lag in following changes in the
expected value of sales. A low value of A gives
weight to many and therefore older observations;
the larger sample size will reduce the random
variability thereby giving greater accuracy in estimating