Material Allocation Based on the Lot Expiry

Hi Experts,

I have a below scenario,

The Item XYZ - 200 Qty, Lot is Expiring in 100 Days from now, Available In-Stock
The Item XYZ - 450 Qty, Lot is Expiring in 70 Days from now, Available In-Stock
Total On-Hand Stock for Item XYZ is 650, with different Expiry

Picking Rule created with Shelf life as 90 Days, the Pick Rule Assigned with Specific Customer -ABC

I have demand from customer - ABC for item XYZ - 250 Qty, when i release the pick slip, it is releasing only 200 Qty with Lot expiring in 100 Days, the remaining 50 Qty is backordered. If no stock is available with Shelf Life 90 days assign the lots shelf life days less than 90 days stock.