FIFO (First-In, First-Out) processes items in the order they arrived. In production, a FIFO lane is a controlled inventory buffer between two steps that enforces sequence and caps WIP — a key building block of connected flow when continuous flow isn't feasible.
FIFO prevents aging, obsolescence, and mixed-sequence defects, and is essential in food, pharma, and any operation with shelf-life or traceability requirements.