ROLLFORWARD
Basic Overview
Description  Rolls the values of OriginalNode forward with the influence of Node1 and other optional Nodes. The rollforward starts after the last value along the finest time level and is done for each shared dimension individually. If Node is not of type percent, the percentagewise differences are calculated relative to the first value of the Node. Both nodes need to have the time dimension available. The dimensions of OriginalNode are retained and determine the dimensionality of the result. Node1 is rolled up according to its aggregation function to match the dimensions of OriginalNode. The difference between this function and ROLLFORWARD_MUL is how they treat multiple influence nodes. ROLLFORWARD sums up the effects and then applies them to the OriginalNode. ROLLFORWARD_MUL multiplies up the effects and then applies them to the OriginalNode New in Version 2.0: the first argument is now optional. The rollforward will work as if a "flat" growth was supplied. See examples of usage at Basic Data Upload & Model Definition, Model OneTime Effects to Correct the Simulation Basis 
Signature  Version 1.19 and before: ROLLFORWARD('OriginalNode', 'Node1' [, 'Node2', …]) Version 2.0 (End of Feb. 2018): ROLLFORWARD('OriginalNode' [, 'Node1', …]) 
Parameters 

Example
Rollforward with a Percentage Node as Input
OriginalNode =
Year  Revenue 
2016  95 
2017  100 
Inflation (Unit:Percent) =
Year  Inflation in % 
2017  0.02 
2018  0.1 
2019  0.2 
Output ROLLFORWARD('OriginalNode', 'Inflation')
Year  Revenue 
2016  95 
2017  100 
2018  110 
2019  132 
Rollforward with an absolute Node as Input
Market in EUR:
Year  Market Size 

2017  10000 
2018  10100 
2019  10500 
Output ROLLFORWARD('OriginalNode', 'Market')
Year  Market Size 

2016  95 
2017  100 
2018  100+(10100/10000) = 101 
2019  101+(10500/10100) = 102,03 
Rollforward with multiple driver nodes
When working with multiple drivers, the effects are calculated and applied individually per timeframe (e.g. year).
Inflation in Percent:
Year  Inflation 

2017  10% 
2018  10% 
2019  10% 
Growth in Percent:
Year  Growth 

2017  20% 
2018  20% 
2019  20% 
Revenue in EUR:
Year  Revenue 

2017  1000 
ROLLFORWARD('Revenue','Inflation','Growth'):
Year  ROLLFORWARD(...) 

2018  1000 + (1000 * 0.1) + (1000 * 0.2) = 1300 
2019  1300 + (1300 * 0.1) + (1300 * 0.2) = 1690 
See the Combined Growth Pattern if you prefer to have the effects "influence each other" in the respective time frame.
If 'Node 1' relates to a EUR node, it will lead to unexplainable results.
See also: Simulate Future Values of your Data with Rollforward , Model OneTime Effects to Correct the Simulation Basis, Creating a Model with periodic Loops