the effective to date on sourcing rule

Is there any document that I can refer to for the explanation of how allocation happened during planning process for below case?

1, sourcing rule for a buy item created with different effective to date (end date), and there are different suppliers and allocation rates within each period

2, this sourcing rule assigned with the buy item

3, buy item has processing lead time and post-processing lead time, and suggested dock date on ASCP workbench will be need by date on PO document

4, in this case, while ASCP performs planning process to generate planned order and match suggested due date with each period, not consider suggest dock date (need by date on PO)