Best method to calculate an ending from a starting quantity on items
I am building an FM Go solution.
There is a table called Load. There will be a truck that is loaded with a Load::Qty, Load::Item, and Load::Description filled out. There is a separate TO that creates a relationship of Load Sheet to Load Items through the Line Items table.
I created a field, Load::Status with a checkbox for "Starting" and "Ending". The first record would be checked as "Starting" and the next one would be "Ending".
Throughout the day, items will be sold on invoices. At the end of the shift, the actual quantities would be filled in for the ending amounts not sold. For now, the sales don't affect the starting and ending loads. There will be reporting later to compare the sales with the physical counts that are done from starting and ending loads.
My dilemma. I'm trying to figure out the best way to either report or calculate the difference between starting and ending load. It's probably simple and I'm not adept yet and haven't run into this type of problem yet.
Should "Ending" be a different table or layout? Should I create a different layout and make calculation fields to subtract starting from ending?