For some items it may be known that the underlying medium/long term trend is flat i.e. it will show no significant rise of fall in the medium/long term. This model is designed for such circumstances.
The estimated trend value for any period is obtained by taking a simple average of adjusted historical adjusted data. The forecast value any month is obtained by applying appropriate seasonal and special factors to this estimated average trend value.
An example simple average trend graph is shown below.
Please sign in to leave a comment.