Changing the BCWS
Paul D Giammalvo, Professor and Consultant, Indonesia
Sorry Major, but you should NOT change the BCWS at all... That is and should remain your baseline, against which you measure, assess and evaluate your BCWP and ACWP.
The bigger challenge is how to match your ACWP against the BCWP. Using the 50/50 rule you will have earned 50% of the BCWS for that activity, but will have no ACWP to charge against it, making it appear in the beginning that you are ahead of schedule and under budget and you won't know for sure what your CPI and SPI are until after the activity finishes.