FIFO follows receipt; FEFO follows expiry
FIFO gives priority to stock received first. FEFO prioritises the nearest expiry date. They may produce the same choice, but not always.
Suppose Monday's receipt expires at the end of June while Thursday's expires at the end of May. Under expiry-based selection, the later receipt has priority, provided it meets the order's other requirements.
The rule needs batch-specific data
A general product date is insufficient when deliveries have different expiry dates. Quantity, batch and location need to remain connected so the operator can find the selected stock.
Consider the customer's required remaining shelf life too. The nearest expiry does not automatically make a batch suitable for every order. Stock awaiting quality assessment should not be selected simply because its date is earlier.
Test the selection on actual deliveries
Choose a product with at least two batches and different dates. Check the picking suggestion, physical availability and issue record.
For a warehouse manager, this establishes whether rotation works in daily operations rather than only in a procedure. WMS can consider expiry when selecting stock, but requires reliable data and agreed exception rules.