s-curve topic

hi..
This coming September marks the 2nd year of my profesion as the scheduler in oil/gas industry.

i understand to calculate the weightage but i don’t know how to determine the daily planned value % vs the actual value % to develop s-curve. For the time being , all my projects are lump sums basis and using manhours as my budget qtty. I usually reporting to the sr. planner on daily project progress using P3 Software.
Appreciate if somebody can give me clues how to calculate for the above.

Thanks!