The split would put the Available Stock, Supply, and Demand sheets into their own workbook. I'll call this "ATP" workbook from now on. The Item Sales, Customer Sales and other sheets would remain in the original workbook.
the Sales Analysis tool doesn't perform well for large customers; splitting it in two will increase the performance
the tool is usually used for sales analysis, or planning - but not both. the split would accurately group these two functions in separate workbooks
there have been multiple requests to see the sheets within the ATP workbook in the BBL and CE equivalents. I don't know if there is a good design to work it into an existing sheet, but I did make a separate sheet (exact copy of) the Available Stock tab but in BBLs. If we need more sheets, then a separate workbook would be nice so the first one doesn't get any bigger.
The new ATP workbook should have a Week Start field in the Date data set. Many customer plan by week; and a default sheet with that as an example.
The Demand data model should take into account batch status. For example, if a batch of 100 units expires on 4/16/20, then on that day there is -100 demand for that item.