I hope that you can help me out?
I am working on a project and creating a forecast for the budget and duration. During the project I want to fill in the real cost/duration, even when its higher. Is there a way to do this without the forecasted budget or duration being changed?
You can use the baseline feature to store your original budget and estimates: https://support.office.com/en-us/article/Set-and-save-a-baseline-AC855151-34F2-42E8-8B05-C363DCED308...
Then you can use various views and reports to compare your current schedule and progress against the original one stored in the baseline.