I assume you are expecting it to do something like this:
Cost Code X, Quantity Y
Change Commit - refers to SOV line
Cost Code X, Quantity Y+Z
Don't think that will happen as the Quantity field is not a formula field. You may need to pull that into the detail form of the change commit and have a formula in your detail form field to calculate the new quantity, then pass that back to the SOV.
Could you eloborate little more on it. How do we create a formula for the quantity ?
Looking at it again, I don't think you can. Quantity is not something that auto-populates to the SOV.
Thanks for the quick response. I appreciate your help.