Yes, you are correct. Sounds easy but it is not. One approach would be to have a set up a bunch of of fields on the Project record such as
[Hours Reqd Current Month]
[Hours Reqd Current Month +1]
[Hours Reqd Current Month +2]
[Hours Reqd Current Month +3]
Then you can have a report which shows the hours required each month relative to the current month. Not sure if that can be turned into a chart, but it will give you a decent report.