Trend (Linear or Straight Line)
The trend forecasting method is based on the
linear regression technique of time series forecasting. Trend forecasting
gives the best forecasting reliability when the driving factors of
your business affect your measures in a linear fashion. For example,
when your historic revenue increases or decreases at a constant rate,
you are seeing a linear effect.
A multiline plot of historic data should look linear or close to linear for greatest reliability. For example, if you are forecasting revenue for the next two quarters based on revenue for the past four quarters, and if the multiline plot of past quarterly revenue is linear or close to linear, then the Trend method gives you the best forecasting reliability.
Use the Trend forecasting method when only two data values represent two time periods in your historic data.