I am trying to account the value of a certain amount of grain coming in and out of storage based on the amount of fees. The grain is stored in a lump sum. I am trying to calculate the value/tonne of outcoming grain utilising a first in first out type approach in Excel. I have attempted learning Python for this task but I feel like it will be a while before my ability utilising coding (something pretty foreign to me) will be at the level where I could perform this task.
For example 400 tonnes might come in at a certain value which starts accruing storage fees in May. Then in June there might be 500 tonnes come in and start accruing fees from there. In July I might decide to take 600 tonnes out of storage (obviously meaning that 400 tonnes worth of fees from June and 200 tonnes worth of fees from July). Doing this leaves 300 tonnes of grain still in storage accruing fees, spillover which is then accounted for first for the next calculation. The size of outtakes varies between being larger or smaller than the amount on intakes.
I have tried utilising a sort of mini-grid. Which implements a series of If checks to solve the issue but it's difficult to automate when an outtake requires multiple different intakes of grain (multiple rows in the column) to then go to the next untouched cell in that column after I've taken into account the "spillover" from the previous outtake.
Is there solution here that I'm missing, mainly around taking into account the differing amounts of cells required for a series of calculations?