Performance calculation
 

Hello Gentlemans))
Please share with your experience.
As usual flight crew calculate the T.O. performance before receiving Load Sheet using Preliminary Data (OFP).
Once receiving the Load Sheet, we have new Mass Data which forced us to update T.O. performance accordantly .
In almost all of routine cases we have lower Mass Data once receiving the Load Sheet, then we had on Preliminary Data (OFP).
Can we suspend recalculation concerning no significant changes to lower Mass (example up to 2 tons)?
The similar question to changes of later ATC Clearance for Intersection T.O. It Might be possible to calculate the T.O. performance for shortage distance(conservative intersection) in advance?
And last question the method of Landing Performance calculation. What is the latest time to recalculate the Landing Distance?
One of mentioned time A&Q EASA GRF 10-15 minutes before the landing. Otherwise perform GA or Holding to have the time.
I can see all of mentioned questioned individual position of each operators. However, very ask to share with your opinions and experience if applicable.
The meaning of my question to save valuable time on time critical stages.
Thanks in advance with your possible comments.

We usually calculate TO performance using provisional load sheet data plus a 1000kg additive.
When we receive the final load sheet as long as the TO Weight is less than or equal to the weight we used for calculations we don’t redo the performance figures.

Landing calculations usually done prior to ToD using estimated landing weight. No further calculations required unless the conditions change for the worse. Usually not a problem as we aren’t usually landing distance limited at the airports we operate to.

In our company we calculate new performance when we have a loadsheet if takeoff weight is above from first weight from ofp, and also we should check green dot speed from mcdu and efb, we calculate landing performance when we have actual atis information, it is approximately 15 minutes before TOD.