Gantt Charts: How to display both projected and actual timelines on the same Gantt Chart?

I am developing an executive Gantt chart view of key project activities.   We would like to see both projected and actual timelines on the same Gantt view.    I have data fields on the activities table to identify projected start/end dates, actual start/end dates and which of the activities are milestones.   I also have formula date fields for start/end which are used for to provide the the projected values if the actuals have not yet been entered (which is quite often the case on most activities while the activity is a work in progress).   From this data I can project separate Gantt chart timelines of projected start/end or actual start/end.  We would like to more easily compare the projected vs actual dates so that we can more easily demonstrate the total project affect of slippage.   

Is it possible to have a Gantt chart that displays TWO timelines (projected and actual) for each sequenced activity on the SAME Gantt chart?   

I should add that long term we will also want to have an approved historical set of start/end dates to which changes to projections can be contrasted.   We can certainly compare the details in working reports, however solving the multiple timelines visually in a comparison Gantt chart would be helpful.   Please help.

 

------------------------------
Annetta Coleman
------------------------------