Weighted Modeling 
You use this function to take an amount, grow it, and then allocate the new amount based on the relative weights of the selected cells.
You use the following features for weighted modeling.
Sum to Allocate — The initial sum from which the allocation begins. This amount defaults to the sum of the selected cells.
Weighted Destination — A range of cells that contain relative weights, to which the results of the allocation are written.
By Percentage — Increase of the overall sum to allocate by the specified percentage before allocating.
By Value — Increase of the overall sum to allocate by the specified value before allocating.
To allocate an amount by a weighted factor, open the input schedule and choose Weight from the action pane.