Re-baselining

I am used to make the S-curve in excel as I had problem with the store period performance.
So If You have to re-schedule a new baseline, I suppose a new completion data was agreed or You have to recover some delays. Good You just re-schedule the outstnd work and keep the done.
As It can help You to have stored in a ufficial docs the project hystorical info.
And then the same.

The problem with store period performance is:
If I do not use it P3 spreeding the performance achieved on the past, so if I have an activity started from 2 progress time (let say weeks) anmd 10 ut earned the first week and 40 the second on, P3 spreed 25 ut between the two weeks.
Using store period performance in huge shcedule time by time I have strange error message.

Create a copy of your baseline. Carry out the re-baseline works on the copy.