Forecast method: time-series analysis

LN calculates the demand forecast according to the Time Series Analysis forecast method based on the average demand and any earlier defined trend influence and seasonal influence.

The demand forecast is computed as follows:

Without trend influence:

TD(t) = AV

With a linear trend influence:

TD(t) = CS + TF * t

With a progressive trend influence:

TD(t) = BS * TF ^ (t-1)

With a constant seasonal influence:

FD(t) = TD(t) + SF(t)

With a progressive seasonal influence:

FD(t) = TD(t) * SF(t)

Where:

AV	average demand (*)
CS	constant demand
BS	base demand (the estimated demand for period 1)
TF	trend factor
SF(t)	seasonal factor for period t
TD(t)	trend based demand for period t
FD(t)	demand forecast for period t

(*) The average demand is the sum of the historical demand figures by period, divided by the number of periods with demand history.