Clearing the entire bin when pick is short

I am not sure how the user can know that the bin has 20 book inventory when he is supposed to pick 5 and 5 are present for his pick

If by any chance he knows, then he should inform the warehouse manager to plan a physical count in that bin.

I have not seen any option to accommodate this scenario directly.

SAP has a Zero Stock check as physical inventory method, which is triggered if the TO reduces the book inventory to zero, which is not the case with you, as the book inventory is 15 after picking.

And SAP knows a Continuous inventory at putaway, but you are actually picking.