Forecasting involves making projections about future performance on the basis of historical and current data.
The chart below is a synthetic (same as fake) Cost Performance Index at the program level 2½ years. The area on the right is the forecast of possible values of the CPI given the historical behaviour, with tuning parameters and smoothing functions.
The next step is to use real program performance data over some realistic period of time - say 4 year - and use H-W (or a similar forecasting tool), to confirm that a less that complete assessment, say take 2 years of data, forecast a 6 month value, and see of the actual 2 year, 6 month value come out close the to the forecast.
This is all done in R, with very simple commands, once the time series for the CPI is formatted and partitioned properly.
