If you are working with projects then working out what cost control mechanism that will work for you is something that you might want to experiment with. There is both forecasts and budget. There are subtle differences in the detail that you can put against each. As well different ways they integrate with other modules in AX.
It’s worth understanding how they both behave relative to what data is displayed in forms. For example the cost control form and the project budget balances form.
Here is a quick overview.
AX2012 R3 CU11